A Hidden Move (Or HM for short, of course) can be obtained in various ways, most commonly by NPCs during an event or by willingly talking to them. Many of them are acquired during the story-line by your rival or some have hints to show that the HM may be on or in the ground somewhere. (Like Rock Climb in Route 217)
Possibly Thunderstruck - AC/DC. Not an orchestra, but your description only bring this to mind.
Hm 01-cut hm 02-fly hm 03-surf hm 04-strength hm 05-flash hm 06-rock smash hm 07-waterfall hm 08-dive
All the HMs in Pokemon D/P and even Platinum are below: HM: Where to find: Cut : From Cynthia when she comes to Eterna Fly : Galactic Warehouse in Veilstone Surf : From Celestic Town Elder Defog : From man in Pastoria Marsh Rock Smash : Mountain Man at Oreburgh Gate Waterfall : Jasmine on Sunyshore Beach Rock Climb : Route 217 (near Snowpoint)
There are 8 HM's: Hm 01: Cut Hm 02: Fly Hm 03: Surf Hm 04: Strength Hm 05: Defog Hm 06: Rock Smash Hm 07: Waterfall Hm 08: Rock Climb
There are 9 HMs HM:01 Cut HM:02 Fly HM:03 Surf HM:04 Strength HM:05 Flash HM:06 Whirlpool HM:07 Waterfall HM:08 Rock Smash HM:09 Rock Climb
HM 1=Cut HM 2=Fly HM 3=Surf HM 4=Strength HM 5=Flash HM 6=Whirlpool HM 7=Waterfall
Which hm?
HM#1. Cut HM#2. Fly HM#3. Surf HM#4. Strength HM#5. Defog HM#6. Rock Smash HM#7. Waterfall HM#8. Rock Climb
hm : how much hm: huge me
HM stands for Heavy Metal
HM stands for Hidden Machine.
HM