Fascinating remark. I don't have perfect (abs) pitch and never heard of the relative variety. But I grew up playing piano, mostly on my own time, which means I'm extremely comfortable playing anything I hear in C, and just slightly slower at repeating things in A#. My brain has to transpose. But now I play pedal steel slide, and I have a trick to picking up any song quickly. I find the root chord of a song and intentionally forget what it was... so I'm not playing in F or A. I remap my brain at the start of that song to remember that tone as C. And then I can find everything without thinking about it. If I think "where's the 7th of C#" I'd have to do a few steps in my head. But once I've got the hands synced with an artificial idea of "C" I know exactly where my options are. So in a way it really may be better than perfect pitch, because I can remap a song's scale to a keyboard in my head and then strum one or two times between songs and "remap" the "C". I realize that makes me uh... hahah not Mozart. But it works to let me forget what I'm playing and just play.
Same experience here with a pedal steel. That's why I am now pushing my bandmates to adopt the Nashville Notation System which only deals in relative position of chords in the scale[1].
Hah! I love that there's another PSG player on HN who gets this right away... that's awesome. I never heard of this system specifically... I feel like a singer holding up 3, 4 or 5 fingers has been the way I've been cued lots of times to changes in a song I barely knew, without me even thinking that was a system. I bet they didn't either.
Separately, I know zero music theory... but PSG really was what let my brain get comfortable with a 3rd of a 4th being a 6th that was two frets down from the 5th of the root... I think probably engaging your knees and ankles in reaching for the physical positions in time builds almost like a muscle memory of the musical relationships... like the kind of control you get driving a manual car... but only if you already have the tones you're looking for in your head, and you know where you're going. PSG is the most mindbending realtime puzzle to play... so it makes sense that players need tricks to know where to go from a certain position (especially if you find yourself stuck in one when you jump into a song)
I learned about that in the Paul Franklin online course (expensive, but worth the money if you are unable to find a personnal teacher, yay europe).
I don't have absolute pitch (and a crappy relative one), but this "standardisation" based on the root note really helps build a knowledge of how chord changes "feel". I suspect this is what builds this ability to easily find the right notes when improvising.
Weel anyway, always happy to find people keeping the steel alive !
I play guitar. I amaze people when I say I have no idea what notes I'm playing. I know the Nashville Number System (learned it before knowing it had a name) and use that. So going back to your example - I find the root and that's my 1. Next I look for does it have a 3 or b3, i.e. is it major or minor? That'll drive me to a major pentatonic or minor pentatonic. For a lot of songs you can stop there. There's a note that's outside of the pentatonic? That'll indicate your mode.
The nice thing about the Nashville Number System and guitar is once you have this information and know what your 1 is it's a set of patterns. You can put my 1 anywhere on the fretboard and I know what to play. Makes transposing super simple too.
Bottom line - I think in intervals, not notes. When playing a song by ear, which is how I mostly play, I could be off by a semitone or two but it doesn't matter: point our where the 1 really is and I'm still good to go.
This sounds very similar to how DAW (digital audio workstation) software has features to "transpose" pitch. You essentially just move one of the notes to where you want it to be and all other notes get transposed relative to it.
