Different streaming platforms have different audio file requirements. In order for your audio file to be accepted by all platforms, you should adhere to the following specifications:
File format: WAV file
Sample size: 16-bit or 24-Bit
Sample rate: 44.1 kHz
Data transfer rate: 1411 kbps
If you're exporting your own audio file from your DAW, do make sure to choose the correct file format and sample size: WAV and 16-bit or 24-Bit.
To convert your audio file to the correct format using iTunes, follow this step-by-step guide:
Open iTunes (or Music if using a newer iOS) on your computer.
Select the song you want to convert and highlight it by clicking once on the song title. It should now be highlighted in blue.
Open your preferences under "Music" --> "Preferences".
Select the folder "Files" and then click on "Import settings".
Under "Import with" you can now select the option "WAV encoder".
Under "Settings" select the option "Custom". Here you can adjust the sample rate to 44.100 kHz, the sample size to 16-bit or 24-Bit and the channels to stereo. Click OK until you get back to your iTunes overview.
With your title still highlighted, click on the drop down menu "File" (top left of your screen) and "Convert", where you can select the option "WAV Version".
Your song is finally converted and ready to be uploaded to MusicHub!