Answers

1. Root Canals
2. Tree root
3. Radical Departure
4. Radical Dude
5. Long haired hippy radical
6. Roots
7. Kicks on Route 66
8. Root beer (Dos Equis)
9. Root crops
10. Root cellar
11. Ruty Huxtable
12. Rutabaga
13. Fruit Salad
14. Rootaceous
15. Crouton
16. Brute force
17. root top
18. Root root root for old Notre Dame
19. Money is the root of all evil
20. Routine
21. I root for you too
22. Rotisserie

A thank you to XBigBear for providing the music.  I think it is the only mathematical song he knows.