Hi Chiron:
No, music is not recommended to be intentionally used during deep meditation. It can divide the mind and impede the process of attention going beyond the mind to inner silence. Here are a couple of lessons that discuss it further – covering all sensory inputs introduced intentionally in deep meditation that can divide our attention in practice:
http://www.aypsite.org/37.html
http://www.aypsite.org/31.html
This does not mean we can’t meditate with inner or outer stimuli present. The procedure of easily favoring the mantra when we realize we are off into thoughts, feelings or sensations takes care of this. But we do not intentionally introduce stimuli into our awareness.
With good deep meditation, according to the simple procedures of practice, we will benefit even more when listening to the music afterward, as discussed in the second question here:
http://www.aypsite.org/161.html
The guru is in you.