1. "Mull of Kintyre," Paul McCartney and Wings: Bagpipes
2. "Bohemian Rhapsody," Queen: Gong (The very last note of the song)
3. "Maggie May," Rod Stewart: Mandolin
4. "Living in the Past," Jethro Tull: Flute
5. "I Think I Love You," Partridge Family: Harpsichord
6. "The Streak," Ray Stevens: Banjo
7. "Fingertips - Pt. 2," Little Stevie Wonder: Harmonica
8. "Good Vibrations," Beach Boys: Theremin (it's that weird whistling sci-fi sound at the end)
9. "Please Don't Go," KC and the Sunshine Band: Harp 
10."Hooked On A Feeling," B.J. Thomas: Electric sitar
11. "For No One," Beatles: French Horn
12. "Dust in the Wind," Kansas: Violin
13. "Send In The Clowns," Judy Collins: English Horn
14. "Beginnings," Chicago (two): Trumpet and Trombone
15. "When I'm Sixty-Four," Beatles: Clarinet and Bass Clarinet
16. "I Got You Babe," Sonny and Cher: Oboe
17. "Under My Thumb," Rolling Stones: Marimba

Bonus: "Tusk," Fleetwood Mac: An entire marching band! My friend Sam Hozman would kill me if I didn't mention it was the Marching Trojans of USC; he's an alumnus of this band.