You can have a ringtone for your incoming calls then notifications. To do this (with your own provided music) connect your droid to a computer and transfer music to the device. From music you can set as phone ringtone. Since you want ringtones for notifications you can get a free application called Ringdroid which will load your music to it, you can pick whatever part of the song you'd like to use. At that point you can save it as a notification tone