If you play music, you know what a time signature is. The typical song is in 4/4. It's counted as 1-2-3-4, 1-2-3-4. Waltz or some western swing is in 3/4 time ... 1-2-3, 1-2-3. But this song, one of the most famous jazz compositions ever, is in 5/4 time ... 1-2-3, 4-5, 1-2-3, 4-5. Very cerebral. Very cool, daddy-o (to borrow phrasing from the era). Enjoy. Follow along if you can.