Not to be outdone, Geddy lee added assloads of keyboards to the mix, but how do you play these while also playing bass?
Well, in fact you don't. In some parts of Rush's tunes, the bass drops out and the keyboards come in - think Subdivisions, or Tom Sawyer.
But there are also songs like Xanadu, that have keyboard padding underneath the rest of the song. In the old days when I was young and dumb I used to think they were pre-recorded, triggered by the sound guy somehow. But it turns out that Geddy and soon guitarist Alex Lifeson were actually playing these sounds with their feet, using a product from Moog caled Taurus Pedals.
These allowed the band to play basic keyboard parts with their feet while their hands were busy earning them guitarist and bassist of the year awards from various magazines. Pretty cool.
Later (and to this day), these pedals also trigger sounds. Some of them are short bursts of sound like the intro synth that accompanies Tom Sawyer. In fact, listen to that song and catch how many times that synth patch triggers throughout the song. It's a lot.
But there is no tempo to it - it's just a whoosh of sound. Rush also triggers sounds that they have to actually play along to, and that's where things can get weird.
Anyway, Moog posted three great interviews with Geddy where he talks about the use of the pedals and their evolution in Rush's sound. It's pretty interesting. Dig it!