No, not in the way you want, it's a phone first and iPod second. Since the speakers and headphones are used to play your ringtone the only way to get back to your music would be to hang up or ignore your incoming call(Which I've never actually paid attention to whether you can do that) and then the music might resume but you will be interrupted.
What you can do is put it in airplane mode which will turn off your phone and wifi so you can listen to music but in that mode no one will be able to get ahold of you by phone, text, etc.