how do i put a ringtone so when people call they hear music

That is a carrier feature. Verizon calls it "Ringback Tones". Call your carrier.

Do you mean put a song as your voicemail message?

If so check with your service provider.

If not, you can't make the people who are calling you hear the ringtone you have put for them (unless of course they are in the same room as you are).