Airdrop music

You cannot send music from streaming services such as Apple Music or Spotify via AirDrop.

If you have a music file saved in the Files app, it can be sent via AirDrop. Long press the file you want to send and select "Share" and tap AirDrop. Remember that the iPhone you are sending the file to must have activated AirDrop, and had you saved as a contact, alternatively the person must have activated "Everyone for 10 Minutes" in AirDrop.

This can be done in the Control Center, or here:

Settings → General → AirDrop → select "Everyone for 10 Minutes"

You can find more useful information here:

How to use AirDrop on your iPhone or iPad - Apple Support

That is impossible, since music is copyrighted and cannot be freely transmitted.

How to use AirDrop on your iPhone or iPad - Apple Support

Adding to JS-from DK’s response:

He said “If you have a music file saved in the Files app, it can be sent via AirDrop.”

That is true. However, the file may well be protected by Digital Rights Management (DRM) encoding, which for the reasons I stated above, would make the file inaccessible to an unauthorized user.