FAQ

Feelism is a Windows app for playing a jazz session with a band at home. Sax, piano, or bass — connect it, and the rest of the band listens to you and answers in the moment.

The aim is playing with someone else, at home, whenever you want. It goes further than an app that only plays backing.

What is included at the start is mostly practice forms (Blues and the like). You can add tunes from the Forum, or bring in chart files you already have. For the order of the screens, start with What you can do in Feelism.

The main difference is that the backing is two-way. In an app that plays the same accompaniment over the chord changes, the band stays the same when you play. Feelism listens to you, answers with fills, and changes how the band is put together as the energy rises.

The other difference is that the answer is not late. In a session, 10–15 milliseconds of delay is enough to break it. From the moment Feelism receives the sound until it answers, the work stays on this computer, without a gap. It does not use a cloud service that makes music. Your playing is not sent over the internet.

In the headphones, your live sound and the band come back together. That mix is there so you and the backing band feel like one.

For the screens, go to What you can do in Feelism.

The path is as follows.

1. You play your instrument
2. The sound goes through a mic or a cable into an audio interface (gear that puts the instrument into the computer and sends sound out to the headphones)
3. From there it crosses into the computer, and Feelism hears it
4. Piano, bass, and drums change the accompaniment and the fills to match how you play

Near the top right of the screen, short bars and numbers for In · Return · Out are lined up. When In is moving, the sound has reached Feelism. When it is still, the band cannot hear your playing.

Direct Monitor on the audio interface (it returns incoming sound to the headphones inside the box) does not count as input by itself. The same sound has to reach Feelism. Details are in What you can do in Feelism.

Your playing is not sent. Neither the sound nor MIDI goes to Feelism's servers. The band's answers are made on this computer.

The internet is used for things other than sound: license checks, notices, Forum packs, contact, and the like. See the Privacy Policy.

When you leave a little space, the band answers briefly. On screen this is Fills. You can choose which instrument answers, and from which chorus. With it off, the band only accompanies, and leaves the gaps unanswered.

When the piano answers, it stops comping for a moment. Same as a live session with one pianist.

Fills, and Trade (taking turns soloing for a set number of bars), are separate settings. The controls are in Fills.

Dynamics on the screen is how the band decides which step it is on, from how you play. You can set the starting point from "pp quiet" through "ff build". It steps up at a chorus boundary when you played during that chorus. When you put nothing in, it stays at the start.

Changing gear is a change of the band's setup, as well as the volume knob: drums move from closed hat to ride, and bass from 2-feel to walking. As it builds, the amount of playing and the register change too.

What the band watches to judge the build depends on the instrument. Wind uses volume. Guitar and bass use density and register. Voice uses register and density. Keys lean on velocity and density. Choose what you play in Settings → Input instrument.

It does one at a time. Feelism's piano is one player. It either comps or answers.

When you comp on keys yourself, uncheck Piano in Settings → Band. Feelism's piano stops, and bass and drums remain. To lower only the level, use Piano in Mix.

Wind instruments come first because the time until the pitch is known is relatively short. Low notes on contrabass or electric bass take time for the pitch to settle, so the response can feel slow.

Guitar, voice, and keyboard also work. Choose what you play in Settings → Input instrument. The weights used to judge the energy switch to suit that instrument. This setting is separate from how a transposing instrument is read, and from the sound.

It does not. What Feelism makes is a sequence of notes (which pitch to play, and when). The tone is played by a sound source on your computer. It does not use a cloud service that generates a waveform of a tune.

The reason is delay. A session falls apart when the answer is heard late. Making the waveform on a distant server and sending it back cannot avoid that delay.

A computer cannot take mic or instrument sound as it arrives. An audio interface is the gear that puts that sound into the computer and sends the computer's sound out to headphones. You connect it with USB.

The box usually has these jacks:

• Input … where you plug in a mic or an instrument. Labels include INPUT, MIC, INSTRUMENT, and Hi-Z
• Output … where you plug in headphones. Labels include OUTPUT and PHONES

For Feelism to respond, the sound has to reach the inside of the app. You can try the computer's own mic input. The delay there is large, and playing tends to be hard. An audio interface is the recommendation for the real session.

How to connect: Connect a PC and an audio interface. A photo example: Connection example (Studio 24c).

A driver is software that lets the computer use a peripheral. Here, the peripherals are a mic, headphones, and an audio interface.

ASIO (Audio Stream Input Output) is a standard for audio input and output, proposed by Steinberg. On an ASIO-compatible audio interface, the maker's ASIO software carries the audio with a small delay. The delay is clearly smaller than Windows' ordinary speaker settings.

In Feelism, choose ASIO as Driver in Settings → Devices. Choosing an output whose name includes ASIO does the same thing. Install the ASIO software supplied by the maker of your audio interface.

Switching the driver or the output can produce a sudden, very loud sound. Take the headphones off before you switch, or lower Gain.

It is optional. Without an audio interface, you can still hear the accompaniment on the built-in keyboard. You can use that to check that the app makes sound. How to open it: Play with the built-in keyboard.

A real session, where you play and the band answers with fills, needs a low-delay input. The computer's built-in mic and wireless headphones tend toward a large delay. For the real session, an audio interface and wired headphones are the recommendation.

Both are ways to hear yourself in the headphones. The path is different.

• Self-mix … inside the computer, your sound is mixed with the band and returned to the headphones. This is Feelism's starting setting. You set the level (Return level) and the return reverb in the app. Your sound makes one round trip through the computer, so it is delayed by a very small amount
• Direct Monitor (the interface may label it Monitor or Mix) … the incoming sound is sent straight to the headphones inside the audio interface. It does not pass through the computer, so the delay on your own sound is almost none. On its own, this is not an input to Feelism. The same sound still has to reach Feelism over ASIO

The band responds when In on the screen is moving. Hearing yourself right away, and Feelism hearing you, are separate. With both left on, you hear yourself twice, at two different delays.

The comparison and how to switch are in Self-mix and latency.

When ASIO cannot be chosen as Driver in Settings → Devices, the computer's ordinary audio output is used. Often the ASIO software that comes with the audio interface is missing, or the device does not support ASIO.

You can still hear the accompaniment on that ordinary output, with more delay than ASIO. It is a poor fit for a real session. Install the ASIO software as the maker describes, and set the driver to ASIO. If you still cannot choose it, check the device's instructions first.

Before you switch the driver, take the headphones off or lower Gain. A sudden loud sound can occur.

Plug them into the audio interface output. The jack on the computer itself is a different path.

Feelism's sound comes out of the output of the device you selected. With the driver set to ASIO, headphones on the computer itself leave the band unheard. Headphones are the place to start. The computer's speakers make it easy for the mic to pick up the band and feed back.

It is a poor fit for this. Wireless delay is large, and playing gets hard. Use wired headphones, plugged into the audio interface output.

The current release is for 64-bit (x64) Windows 10 or 11. 32-bit Windows, and Windows 7 / 8, are outside the supported set. The screen needs Microsoft Edge WebView2 (many computers already have it).

We expect a typical Intel or AMD Windows PC. Windows on ARM has not been tested. Get it from the Microsoft Store (details: Get the Windows version).

The first instrument we had in mind is a wind instrument (sax and the like). Connect a mic or a pickup to an input on the audio interface.

Electric guitar, electric bass, vocal, a line from an electronic piano, and a MIDI keyboard also work. Choose what you play in Settings → Input instrument (this is for judging the energy. It is separate from the sound and from Transposing instrument).

Where each instrument plugs in is under Connect in the manual. Wind: Wind instruments. Guitar and similar: String instruments with a pickup.

In Feelism you choose the groove and the number of beats in a bar separately. On screen, the groove is Feel, and the number of beats is Meter.

When you pick a Feel, the bass walking, the drum pattern, and how the piano enters all change together. Besides Swing, Bossa, and Ballad, there are Disco, Organ trio, and others. Meter and Feel are chosen separately, so a 3-beat bossa nova is one combination you can make.

Meter is the number of beats in one bar: 4/4, 3/4, 5/4, 6/8, and so on. It cannot be changed during Play. Press Stop, then change it. The list and the controls are in Feel and meter.

Double-time is playing where the tempo and the flow of the chords stay as they are, and only the band's subdivision gets finer. To raise the tempo itself, change the BPM number.

Feelism has two.

• Force double-time … while it is on, the finer subdivision stays on
• Auto double-time … when the solo gets busier, the band matches from the end of the chorus

Both start off. During a 2-feel section, double-time does not engage. How to turn it on: Double-time.

There are two kinds. You can use them together.

• Transpose … moves the band's sound and the chord names on the chart together, by semitone (−6 to +6)
• Transposing instrument … for instruments such as alto sax, where the written chart and the sounding pitch differ. It shifts only how the chart looks. The band stays in concert pitch

Tenor sax and trumpet use Bb. Alto sax and baritone sax use Eb. There is no octave choice, because the chord names would stay the same. The controls are in Transpose.

Yes. The built-in keyboard can play the accompaniment. It is a check that the app makes sound. The full session, where the band answers the sound of your instrument with fills, is a separate experience.

How to open it: Play with the built-in keyboard. From install through Play: Up to your first session.

Yes. It sends which key you pressed, and how hard. The sound itself stays out of the message. On screen it is the keyboard labeled MIDI.

Chords arrive accurately. Pitch heard from a microphone is unsure on chords. It fits when you want a sure response. How to connect: MIDI keyboard.

Yes. Practice forms (Blues, Rhythm Changes, odd meters, and practice tunes in various grooves) play without paying. These 6 named standards are also free: Doxy / Well You Needn't / Old Devil Moon / Someday My Prince Will Come / Take Five / On Green Dolphin Street.

Looking at charts, rewriting chords, transposing, recording, and importing chart files can also be done without paying. What locks is Play. Extra standards (about 90 tunes, planned for early November 2026) and imported tunes (from your own files and from the Forum) need a subscription. For the schedule, see When do the extra tunes arrive?.

Details are in Paid tunes and the lock.

The monthly plan is for adding tunes, on top of the free practice forms and 6 standards. An add-on pack of about 90 jazz standards is in preparation. Release is planned for early November 2026. Playing an imported add-on pack needs a separate plan. Looking at the chart can be done without paying.

Practice forms and the 6 free tunes stay free. For the price breakdown, see Pricing on the home page.

For customers outside Japan, the Windows version is $4.99 per month. The amount you are actually charged is what the payment page shows. The smartphone version will have a different price later. About 90 extra jazz standards are planned for early November 2026 (When do the extra tunes arrive?).

You sign up from New subscription in the app. The card is entered on the payment page that button opens. Pasting a key is covered in License key.

It is where volunteers exchange practice packs. Open it from Forum in Feelism (next to Find a tune). You can also read it in a browser. Sign-up, login, comments, and posting a pack can be done from the browser. Import a pack and Save ZIP are done from Feelism's Forum.

A Forum account does not require a subscription. Import itself can be done without paying. A subscription is required from the point where you Play an imported tune.

The steps are in Forum.

Yes. Feelism reads uncompressed .musicxml (it cannot read compressed .mxl). Import can be done without paying. A subscription is required from the point where you play with the band.

How to bring in your own files: Tunes you bring in. How to write them: Make MusicXML.

They stay. Charts, imported files, rewritten chords, recordings, and settings remain on that computer. When the period ends, paid tunes and imported tunes can no longer be played. Practice forms and free tunes still play.

Cancellation runs through the end of the current period. Leave the key in place during that time. If you clear the key field in the app, paid tunes lock on the spot. The steps are in Cancel and payment.

Yes. Even if a broken computer cannot quit Feelism, the seat frees within about 2 hours. Paste the same key into Settings on another computer and press Apply, and the paid tunes open. If you had already quit before it broke, you can use it without waiting.

Only one computer can play paid tunes at a time. While the first computer is still running, the one you paste later does not open. When you move machines, quit Feelism on the first computer, then Apply on the next.

How to paste the key: License key.

Split it with the short bars (and the numbers) for In · Return · Out at the top of the screen.

• In does not move … fix the cable, the audio interface knobs, and the choices in Settings → Devices first
• In moves, and you still cannot hear yourself … is Self-mix in Mix on? If it is on and still quiet, raise Return level (it starts at 2.5)
• You cannot hear the band … are the headphones on the audio interface output? Is Play running? Is there a 🔒 beside the tune name?

The step-by-step is in No sound, cannot hear it.

The cause is almost always that your own sound is making a round trip through the computer, or how the device is chosen.

1. Turn Self-mix in Mix off (the key is X). Hear yourself on the interface's Direct Monitor, or, on a wind instrument, as the live sound in the room
2. Set Driver under Settings → Devices to ASIO. Check that the output and the input are that audio interface
3. Leave wireless headphones and USB hubs out of the path

The target is 10–15 milliseconds or less, end to end. Feelism does all of the processing on this computer. The steps are in Lag, hard to play.

Even when sound is arriving, the band does not join while playback is stopped. Check Play first.

Then check, in order, whether In on the screen is moving, whether Pitch in Mix is on, and whether Fills are on. Chords, a distorted guitar, and breath noise alone are unreliable for pitch tracking. Try a slow scale, one note at a time.

Low notes (contrabass or electric bass) take time for the pitch to settle, so the response can feel slow. When you want a sure response, there is a MIDI keyboard. How to narrow it down: No response.

Usually your own sound is coming back by two paths at once. A common case is Self-mix left on while the interface's Direct Monitor is also on. Your sound that went through the computer, and your sound that did not, land a little apart and stack.

Use one of them. If the delay is fine with you, use Self-mix only. If the delay bothers you, use only the return on the interface. How to switch: Doubled sound.

In Settings → Devices, switching the driver (ASIO and so on) or the output can produce a sudden, very loud sound. Take the headphones off before you switch, or lower Gain.

After a switch, Feelism lowers Gain and the return level to 0.2 for safety. You raise them yourself. Speakers left open make feedback from the mic more likely, so headphones are the place to start. The same caution is at the top of Connect a PC and an audio interface.