Great video, with loads of wonderful and timeless classic sounds. The guy says there's no particular order.
In short:
1- Procol Harum 'Whiter Shade of Pale'. Hammond M102 played by Matthew Fisher
2- The Doors 'Riders On The Storm'. Fender Rhodes played by Ray Manzarek
2 (tied)- The Doors 'Light My Fire'. Vox Continental & Rhodes Piano Bass played by Ray Manzarek
3- The Allman Brothers Band 'Jessica'. Hammond Organ played by Gregg Allman
4- Gary Numan 'Cars'. Mini Moog bass & Polymoog strings played by Gary Numan
5- John Lennon 'Imagine'. Piano played by John Lennon
6- Pink Floyd 'Echoes'. Piano & Hammond organ played by Rick Wright
7- Boston 'Hitch a Ride'. Hammond M3 played by Tom Scholz
7 (tied)- Boston 'Foreplay/ Long Time'. Clavinet and organ played by Tom Scholz
8- Argent 'Hold Your Head Up'. Organ played by Rod Argent
9- Supertramp 'Bloody Well Right'. Electric piano played by Rick Davies
10- Roxy Music 'Beauty Queen'. Synths (not detailed) played by Brian Eno
11- Stevie Wonder 'Superstition'. Hohner Clavinet Model C played by Stevie Wonder
12- The Rolling Stones 'Angie'. Piano played by Nicky Hopkins
13- Van Halen 'Jump'. Synth (all we know what, but not detailed) played by Eddie Van Halen
14- Led Zeppelin 'Thank You'. Organ played by John Paul Jones
15- Genesis 'Behind The Lines'. Arp Quadra played by Tony Banks
16- ELP 'Lucky Man'. Mini Moog played by Keith Emerson
17- Elton John 'Don't Let The Sun Go Down on Me'. Piano played by Elton John
18- The Beatles 'Stawberry Fields Forever'. Mellotron played by Paul McCartney and John Lennon
19- Yes 'Roundabout'. Organ played by Rick Wakeman
20- Deep Purple 'Smoke On The Water'. Hammond Organ played by Jon Lord
What would you add?