What are the requirements for audio on Apple Music and the iTunes Store?
Quality is important to us at Apple. We expect to receive the highest-quality assets available. Apple Music and the iTunes Store accepts audio with a sampling rate of 44.1Khz and 16-bit or 24-bit resolution and 96, 176.4, or 192 kHz with 24-bit resolution.
Note: If stereo audio source exists, it must be used. If the stereo audio source is not available you must send an audio source with two identical channels for left and right. Single-channel audio will not be accepted.
All audio must be recorded with a Codec qualified and approved by Apple. For more information on audio requirements, see the iTunes Video and Audio Asset Guide.