How long do your phone calls stay waiting in an IVR to make a decision that you need music??
1> Record your greeting, then just add music with a sound editor. Audacity is free.
2> Send callers to ANNOUNCEMENTS module first, play your greeting "please press 1 or 2" then immediately go to your IVR that has music upload as the IVR announcement. Your caller will hear greeting, then will hear music while they decide to press 1 or 2.