If you're a Kirtan-lover or even if you're generally intersted in music - check the following link:
Jap Man Narhare Narhar Swami - Raag Shudh Sarang
This is Puratan Reet Kirtan (Translation for those not familiar with Sikhi: Old School "Sikh Music")
The chorus is first sung in a 15 beat cycle - yep, no type-o: 15 beats.
And then they switch to a fast 12 beat cycle for the verses.
Switching rythmic cycles is an old Sikh tradition started by Our 4th Guru , Sri Guru Ram Das Ji.
This composition is about 350-400 years old.
I dont know about you, but every time I hear it, I get chills (in a good way).
On top of that, If you are in to spirituality/Sikhi etc and understand the meaning - it just takes you to another level.