For comforting the dying, I learned a tremendous amount from this website:

Handbook for Mortals

Both my parents learned a lot from the website before they died too. They found it very helpful to know what to expect.

My mom was in a nursing home for a long time before she died, and was also a musician. She was a singer, and stayed involved with the choir up until her diagnosis with lung cancer. After that, she started to withdraw. By her last few months, she didn't want music or tv or any noise beyond talking voices, really.

At first that seemed terribly sad to me. But when I worked up the nerve to ask her about it, she said she didn't really miss it. She said silence was just more comforting and peaceful to her.

It was from the website above I learned that was OK, even though I thought it sad she didn't want to hear music.

I'm not trying to discourage you in any way. My mom LOVED IT when musicians came in to perform. But not when she was actually dying. So, you may have better luck with the long term nursing home residents, than those in hospice. People in hospice aren't working on getting better. For them, death is the healing part, so they have a very different set of needs.

That's not to say everyone who is dying won't want music! I just think you need to realize that not everyone will necessarily consider music soothing. It really agitated my mom in end stage, although she didn't mind tv in the background. My dad didn't want anything--not radio, music, tv, nothing. He didn't communicate much either, even though he could, and he understood us and communicated right up to the last dying breath he took.