This 1969 Fender Princeton Reverb might have been on more hit songs than any other guitar amp in history

Fender's '60s tube amps are classics for a reason; their crystalline headroom makes them workhorses to this day. But few have seen as much action as Louie Shelton's 1969 Fender Princeton Reverb.

As the in-house guitarist for Motown Records and a key figure on the LA session scene, Shelton has probably lost count of the amount of sessions he's played on; but within them are timeless classics from the likes of Marvin Gaye, The Jackson Five, Whitney Houston, James Brown, The Mamas & The Papas, Joe Cocker, The Carpenters, Glen Campbell, John Lennon… the list goes on.  And Shelton used his Princeton on "pretty much everything" he tracked.

So the chance to get up close with this Fender amp and him is pretty special. Here, guitar YouTuber Rick Hollis did just that.

Even more incredible is it was only Shelton's second amp – and that was only because the first one he had was impractical. "When I first got into the second thing I came straight from the clubs, so I had a big Super Reverb with four heavy Jensen speakers in it," he explained in the interview above. "So as soon as I started getting a number of sessions and having to go from one to another and dragging that big amplifier…" As the Shelton explains, only late Wrecking Crew drummer Hal Blaine had a van service to take his kit to sessions at the initially.

"The reason the little Princeton was so practical was in those days we were recording with a lot of open mics in the room, obviously, so we had to play at a low level which meant if you needed to crank an amp up so that you go a bit of dirt… just a little bit of distortion, it was so loud that the engineer would come out and scream at you to turn your damn amp down," added Shelton. "Because it's going in the drum mics and the piano mics."

Shelton's son-in-law worked at Valley Arts Guitars and helped him get around this problem by doing a Paul Rivera mod on the Princeton to give Shelton a master volume (with a gain boost), plus other tweaks including a treble boost. He demonstrates this versatility in action, playing some of his iconic parts on this 1952 Fender Telecaster.

And the mic this legendary player trusted for it all? A good 'ol Shure SM-57. 

But one classic Shelton didn't use it on was the solo to Lionel Ritchie's Hello; that was a Tom Sholtz Rockman; "We just had it sitting on the desk in the control room and plugged into that." Even more surprising was that Shelton improvised the solo. 

"Lionel had hummed a solo he wanted the guitar to play, and he had three other guitar players learning the solo that he hummed," remembered Shelton. "And I did the same thing – I learned that solo and we recorded it [but] to me it didn't sound good as a guitar solo. So I said, 'Just give me another track and Iet me play something else so you'll have an option and we did that one other take'. And that's the solo. It's completely different than what he hummed."