Hi Phil!
We talked a little about music and jhana in this thread, but it was more sharing of experiences than discussion of structured practice. http://dharmaoverground.wetpaint.com/thread/2454410/Jhanas+and+Christian+Prayer
I tried to use songs as objects of concentration, but failed to even concentrate on my most favourite ones for 3 minutes. Now I avoid listening to recorded music most of the time (earworms). Since then I only used Soham-meditation to get rid of earworms, but not as my primary object for long.
I decided to learn from scratch and shifted to visual (kasina) and tactile objects (body).
as for sounded out "musical" objects, I did Om-chanting (not for the last year) for 10-15 minutes. I also did chanting of songs from Taizé. Both are best done in a group. I'd have to try both again since I only got a suitable concentration quite recently, but they both make it easy to settle down, relax and enjoy (even if in the silence afterwards I couldn't concentrate well). I'll recommend your technique to musical friends. Great idea to get rid of the rhythm.
"First you notice that the tuning isn’t accurate." I didn't notice, but I noticed the rhythm would be awry all the time. Agreed that it feels annoying if you're used to something else