Will recording as MIDI lose the quality of a WAV?

Question

I've played a couple of tunes of my electric piano, and have recorded them as MIDI files. I would like to convert them to a WAV format, but I'm worried for the following reasons:

• By first recording my music to a MIDI file, does this mean I have lost the finite quality that would be obtained by recording to a WAV file straight?
• By converting my MIDI file to a WAV, would I be able to retrieve the details of my music (such as hard and soft notes), or is the detail lost forever after recording it as a MIDI file?

I would appreciate any help. Thanks.

Answer 1

MIDI is textual descriptions like a book. Letters and numbers. C#5, E4, G3. Instructions that can be read and misinterpreted in any way imaginable. Channel 2, channel pressure 45.

WAV is an audio recording, like an audio book. A recording of someone reading the text out loud or making noises, sounds of birds singing, the reader singing, burping. Sounds you'll have to guess where they came from.

By first recording your music as MIDI, you will be able to edit it like text, read and re-read it, perform it in infinitely many ways, with different instruments if you like. You can send the MIDI file to someone else, and they will make their computers perform it, or even print it out as notation and have a symphony orchestra try and perform the notes and control-change commands.

When you make an audio recording of a performance of your MIDI file, that performance will preserve... one performance of the MIDI file. You can even mix in the sounds of the audience booing at the performance. Every little nuance will be recorded and preserved. But getting the original notes and control-change commands that there were in the original MIDI file won't be possible.

If you have a few kilobytes data storage space to spare, why not keep a MIDI version as well as an audio recording of a performance of it. It may come in handy later, letting you edit it and make recordings of further performances. Or if you intend to be an audio book author, why not keep a textual version of your book as text, in addition to an audio recording of someone or something speaking?

Answer 2

Depending on the MIDI setting and the keyboard in question, the MIDI file may contain a complete transcription of what you have been playing (or more exactly: what the keyboard used from your play to generate the live sound). However, the only way to convert it into a .WAV file sounding exactly like your performance is to record your keyboard when replaying the MIDI file. The best option would be to record its digital production rather than its audio outputs, but the keyboards I know just don't make the digital production accessible.

Of course you can try not using the keyboard itself but some other MIDI device or expander software. Depending on what you use, the resulting audio may sound better or worse than the original. There is also the danger that the MIDI data contains some information (such as registration changes) that are not generally understood by MIDI devices but just by your keyboard in particular.

Answer 3

I'm confused by this question because midi isn't really a sound format. It's a score format, so to speak. The tones are not recorded but really prescribed - they're notes for an instrument to be emulated by synthesiser.

So... in midi (unlike wav, mp3 or ogg) what you've recorded is practically a score documenting what you played, not the sound itself. (You can even open this score as sheet music in Musescore and probably similar programs.)

I'm not sure how detailed this score is and how close a .wav file will be to what you played if you convert it, but I'm afraid that the actual sound of what you played has never been recorded in the first place. If you've recorded it from an electronic keyboard, then the sound was also synthesised when you played, and it's probably possible somehow (more erudite people than me would tell you how) to use the same sample source for the midi to get the same result. But if it was an acoustic recording, I'm afraid the original sound is lost.

Sorry to be the bringer of bad news.

Answer 4

To address a concern in a comment:

I was just worried that recording the music as a MIDI would remove the subtle differences (such as hard and soft notes) so that when I converted it to a WAV file it would still sound slightly robotic and unnatural...

For most electronic keyboards, the music probably exists as MIDI data from the start. Note, as piiperi's answer elaborates, MIDI isn't actually an audio recording; it's instructions that an instrument or computer program can create audio from. If your keyboard lets you export both formats, they'll probably sound identical when you play back within the electric keyboard, since it probably uses the MIDI data to create the .wav. But you could then take that MIDI file and load it onto a different instrument, or a virtual instrument on a computer, and play it back with a guitar sound, or organ, or sci-fi zap sounds. Some of these virtual instruments might not be able to reproduce the data in the same way; for example, on a pipe organ it doesn't matter how hard you push the key, so a patch emulating one might ignore key velocity.

For one more analogy: If we compare these files to a printed document with words and pictures, then a MIDI file is like a .docx: it has all the words and all the pictures, and you can take the file to a new computer and change the words and and pictures and their order and layout and then print it. A .wav file is like a PDF file: It interprets all that data and locks it into place in one final version. (Or maybe you could say it's like a printout, since technically pdfs can be edited on the full version of Acrobat...)