To be clear, there is a big difference between MIDI and WAV.
A MIDI file is basically a set of instructions for a synthesizer to "play" music in real time.
The instructions define elements like note pitch, note on/off time, instrument sound, etc. A MIDI file's playback can vary. For example, for the piano, a soundfont can include sound samples from different pianos, so one can listen to the same piece played back through a honky tonk piano, a Steinway grand, a Yamaha upright, etc. depending on the sound library (e.g., soundfont) used.
Since MIDI does contain information about note pitches and timings, it can be converted into notation more easily than an audio recording such as .wav or .mp3. (MuseScore can import MIDI files.)
On the other hand...
A music audio file, such as .wav or .mp3, is a digitized recording of the complex sound waves produced by musical instruments. It is essentially a representation of voltages detected by a microphone during recording, regenerated and applied to a loudspeaker during playback. For example, compare the sound (spectrogram) of flute compared to the pure sine wave tone:
In the image, both flute and sine wave show the same frequency (musical pitch). The flute, by producing overtones, has a visibly more complex waveform. In a recording of several instruments, all the different waveforms are jumbled and it becomes very difficult to separate all the combined waveforms from one another. Drums especially, having no defined pitches (i.e., periodic waveforms), are merely noise.
Nonetheless there are attempts to decode audio spectrograms (of .wav, .mp3) into musical notation. Obviously, recordings of a single instrument work best.
See: https://lunaverus.com/
Comments
If it's a WAV file, you will have to just transcribe it by ear, or otherwise find someone who is willing to do it for you.
To be clear, there is a big difference between MIDI and WAV.
A MIDI file is basically a set of instructions for a synthesizer to "play" music in real time.
The instructions define elements like note pitch, note on/off time, instrument sound, etc. A MIDI file's playback can vary. For example, for the piano, a soundfont can include sound samples from different pianos, so one can listen to the same piece played back through a honky tonk piano, a Steinway grand, a Yamaha upright, etc. depending on the sound library (e.g., soundfont) used.
Since MIDI does contain information about note pitches and timings, it can be converted into notation more easily than an audio recording such as .wav or .mp3. (MuseScore can import MIDI files.)
On the other hand...
A music audio file, such as .wav or .mp3, is a digitized recording of the complex sound waves produced by musical instruments. It is essentially a representation of voltages detected by a microphone during recording, regenerated and applied to a loudspeaker during playback. For example, compare the sound (spectrogram) of flute compared to the pure sine wave tone:
In the image, both flute and sine wave show the same frequency (musical pitch). The flute, by producing overtones, has a visibly more complex waveform. In a recording of several instruments, all the different waveforms are jumbled and it becomes very difficult to separate all the combined waveforms from one another. Drums especially, having no defined pitches (i.e., periodic waveforms), are merely noise.
Nonetheless there are attempts to decode audio spectrograms (of .wav, .mp3) into musical notation. Obviously, recordings of a single instrument work best.
See:
https://lunaverus.com/