I have a MIDI digital piano that connects to a computer via USB (it also has a normal MIDI out port too) and I'd like to browse for software that lets me play music through my computer's speakers. I want to look through the options (including open-source candidates).

I just want to pretend it's a real piano and play some sheet music.

I'd like to google for this, but I'm not familiar enough with terminology.

So my question is:

What is the term for software that will convert MIDI input to audio and play it back immediately?

The askers of these questions seem to be seeking roughly the same thing as I am: https://music.stackexchange.com/questions/16229/piano-midi-software How to use my mac and MIDI keyboard as a simple always-on piano Very portable MIDI synth

Is the software that I'm looking for called a MIDI Synthesizer? Or a Sound Module? Or something else?

Another way to phrase it: Given a vanilla install of an operating system, what types of things would I need to install (or run) to get audio output from my piano?

Note: Unlike the other linked questions, this question is not "which software should I use?"

Rather, I'm looking for the terminology so I can solve the question for myself (using search engines).

6 Answers 6


if you want to record and do professional stuffs you go for : DAW (digital audio workstation) , music sequencer or midi sequencer. if you want just play your instrument easily without recording and good sound quality you need to go for : standalone VST (or VSTi) , for example "standalone piano vst". also you can use these VSTs as a plugin in your DAW or sequencer.

P.S : if you are using Mac search for standalone AU instrument (audio unit) instead of VST. in Linux : LinuxVST instead of VST. I suggest you try Steinberg Grand Piano.

  • This seems to be what I'm looking for. So the chain appears to be 1. electronic instrument, 2. USB or other connection, 3. Drivers for that connection, 4. DAW/sequencer/VST/AU, 5. Synthesizer, 6. Audio output drivers/speakers. Step 4 was the one I was missing -- there's already a synthesizer built into my OS. Mar 29, 2014 at 1:29
  • this can be like this : 1.electronic instrument (or midi controller) , 2.USB , Midi , firewire , bluetooth or wireless connection , 3. Drivers 4. DAW (or sequencer) OR standalone VST (or AU) , 5.output. also you can use a VST (or AU) plugin which is not standalone inside a DAW or sequencer (it means use both) but this choice will costs you much more. Mar 30, 2014 at 17:54
  • How do standalone VSTs work? Are they softwares unto themselves? If not, and if there is no native program/ app (DAW/ Synth), what will the VST plug-in to? Pardon ignorance, please.
    – Subir Nag
    Aug 31, 2017 at 8:27
  • @SubirNag standalone VSTs are created to work without a DAW; in some cases they use a wrapper to run and interact with OS resources, sound card, midi, etc. at the other hand in some cases they don't use a wrapper to run the VST but instead they are made to run with their own code base (if you have programming questions regarding to this let me know). actually standalone instruments may not respect to VST standards and they can go further. but VST plugins always should follow some instructions in order to be compatible with VST supported DAWs and only can be run through a DAW. Aug 31, 2017 at 13:06

I believe that you are looking for a software synthesizer, aka soft synth software that receives MIDI data and outputs audio data. You may also need to consider the midi usb software driver software the software that allows one to send/recieve MIDI data across the USB interface and allow it to get to the synthesizers.

In hardware this type of thing may be referred to as a sound module or synthesizer module terminology that may have carried over to the software.


What you're looking for is a software instrument, also known as a virtual instrument or software synthesizer or softsynth. It takes midi input from your keyboard, and generates audio data, either using pre-recorded sounds (in which case it would be a sampler) or generating sound on-the spot (a non-sample-based synthesizer).

Although some software instruments provide stand-alone programs, many are only available as plugins. These will generally be based on VST on a Windows platform, AU on Macs, and LADSPA/DSSI/LV2 on Linux. In order to use such plugins, you will need a digital audio workstation.


The answers suggesting "Midi sequencer" are just wrong. A sequencer is for recording and replaying Midi signals but does not turn them into audio. In a similar vein, DAW or "Digital Audio Workstation" is wrong. While the scope of a DAW is ill-defined and may well come with a Midi softsynth, this is by no means a required component. Indeed, DAW is not even a guarantee for any Midi capability: the popular free DAW software "Ardour" gained some Midi recording capabilities only with version 3. However, pretty much every DAW these days can make use of Midi control surfaces. But those are for things like faders, rotary controls and similar, not musical instruments.

So after expounding on what you are not looking for (at least not primarily), the usual term for converting Midi to audio by software is "software synthesizer" or "Midi synthesizer" or even "realtime Midi player" where "realtime" sort-of suggests that the input to the player is not from a file but rather a Midi device.

In hardware, the term to look for is a "Midi expander".

Note that most of those terms apply for generic converters of Midi to audio. There are some software synthesizers specializing only on particular instruments, doing a lot of work possibly including physical modelling on them. Those can also be called "virtual instruments" and are loosely associated with VST plugins.

How many instruments and which kinds of instruments a softsynth supports is obviously an implementation choice, and even "full GM2 (General Midi 2) support" does not mean that all of the available instruments are useful in production. Particularly stuff like solo string instruments, flutes, and a few other instruments with an expressivity not easily measured in a single parameter (like the key velocity of a piano) are hard to get convincing: instrument sections are easier to get right.

For that reason, there is something to be said for just biting the bullet and getting a hardware Midi expander: something that's 20 years old still has been in the competitive music business for decades. Even if its modeling is not up to modern standards, its playability had to be. And stuff like "latency" had to be well-controlled even then. As opposed to a purely digital solution for song creation, however, you'll have to rerecord the audio signal and then need good quality audio inputs.

But at least the monitoring/auditory feedback will be immediate without configuration hassles, and that makes a difference in playability.


What you are looking for is a "MIDI Sequencer" or more general a "Music Sequencer".

The following is a quote from Wikipedia for "Music Sequencer":

"A music sequencer (or simply sequencer) is a device or application software that can record, edit, or play back music, by handling note and performance information in several forms, typically MIDI or CV/Gate, and possibly audio and automation data for DAWs and plug-ins."

Maybe that is the most general term to look for, but there is a lot out there.

In case you mainly want to play piano sounds, then you might want to also search for "Virtual Piano".

I know you wanted to do the research on your own, but I found this comparison of virtual pianos very helpful:

  • A music sequencer is for writing music on a computer. Not all sequencers will be able to immediately play an incoming MIDI stream, though.
    – Kevin
    Mar 24, 2014 at 16:12
  • See your point, but it depends on your use case. If yours is writing music, then its writing music. Mine is piano playing / practice. As an example: If I only need a piano, I startup Pianoteq. In case I want to practice more freely with some backing vocals or some beats, I use Reaper with Pianoteq VST plugin and load an audio file into a second track and so on. As I wrote, a music sequencer is a very general term to look for and could lead to nowhere. If only a piano is needed then I pointed out the term "virtual piano". Try those in google or youtube and compare yourself :-)
    – Tobias
    Mar 24, 2014 at 19:26

I have written a Windows 10 app to do this, it uses the built in general midi synth or any other midi out it can find


  1. Run the app
  2. Attach your USB keyboard, select it from the list
  3. Choose MS synth and one of the instruments

Away you go

It's not free, but free to try and only a few pennies :)

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