Of course, when I create a performance, it's based in belly dance movement. But, as the music I'm using is often not traditional, I feel it's necessary to put in some non-traditional movement. Your movements should fuse, just as your costuming should fuse. For me, as I dance to a lot of electronic music, I try to integrate into my performances robotic and "electronic-looking" movements, often based in the "popping", "locking", and "ticking" dance styles of breakdancing. I feel it is important to never lose my tribal belly dance posture or arms when executing this movements - because keeping the posture of tribal while performing popping and locking truly fuses the movements. I feel that integrating appropriate movements into my belly dance performances is the only way I can appropriately interpret the music and give the music the credit it deserves for inspiring me to want to perform to it. Of course, this applies to any style of music you choose. If a jazzy piece of music inspires you, research jazz dance, and find ways to fully fuse it with your belly dance movement. If Indian or South Asian music inspires you, look into its history and into classical Indian music. What's most important that you dance to your music as though you were dancing a tribute to the musician who created it. And remember that as belly dancers, it is our duty to become the music, whichever music you choose.
This is perhaps one of the hardest parts about performing: how to lose yourself in the mood of the music without losing control of your dance music. I believe to be able to do this consistently well takes years of training. I've been dancing for more than eight years and I barely feel like I've gotten to a point where I can truly become the music in the way I feel I should. I think there are two issues at hand here. One is that it is very difficult to reach down inside ourselves and share our raw emotions with an audience through our dances. It takes a lot of soul-searching and courage, which can take years to feel remotely comfortable doing on a regular basis. The other issue is finding music that we NEED to dance to, rather than just finding a song that's kinda cool or fun, or something to which another dancer has already performed. Personally, I used to dance to music that I thought was just kinda cool, and my performances to those songs lacked Ooomph. But when I perform to songs that I absolutely love, then that love flows through my body and out to the audience, even if the music itself is sad or angry. Now, when I choose music, it has to make me feel a strong emotion, whether it be anger, joy, sadness, frustration, or longing. The mood the song invokes in me will then be conveyed through my movements, and with appropriate movement and costuming, I can create a complete performance.
One last note on music: Never take music for granted. An artist worked very hard to create that music, and as dancers, I believe it is our responsibility to respect the work of those artists. One of the best ways I feel I can pay tribute to a musician is dancing well to their music. And this lofty goal, of course, takes years of practice, dedication, and straight up love for both this dance and the music to which we perform.