Query about Muslim attitudes toward music

We had a very good time at the "Tear Down The Walls" concert at Hope Presbyterian Church last night, a rock concert-style presentation mainly attracting young people. There were tables with information from a number of local organizations such as Facing History and Common Ground. We also ran a literature table there - Edward and Eunice Ordman representing Temple Israel and Balmoral Presbyterian Church, and Nabil Bayakly representing the Muslims in Memphis organization. We distributed literature about Islam and talked with people about the need to include Islam in interfaith activities and the common values of the Jewish, Christian, and Muslim religions.

While there were lots of Christians and quite a few Jews present (mainly Reform Jews rather than the Orthodox, who tend to get less involved in interfaith activities held in churches), there were only a few Muslims I could recognize. I asked Prof. Bayakly about this, and was a bit surprised by the answer - he suggested that the low participation was not due to what words might be used on stage, but due to the style of music. It turns out that some Muslims have a problems with some musical instruments, something that had never occurred to me. I'm hoping that someone can educate me a bit on this point.