"I can recall the three musicians on the backing track for 'Rock On' all looking around in a mostly empty Advision Studios, Studio 1, wanting to know when the rest of the band were arriving! I explained there weren't any others for that track, and I was relying on them to understand my idea for the production. While the drums and percussion parts were written out, it was definitely Herbie that grasped immediately that a bass guitar playing a lead riff could fill a large part of the spatial spectrum and he took my idea and turned some basic notes of mine, into his amazing bass riff. Then to top it off, he suggested playing it again an octave higher. So you get this unusual bass sound right up front – now it couldn't have been up front if the arrangement didn't allow the air and the space to be created that way."[5]
Song written by Essex himself which was a big hit in the 70s. Bass by Herbie Flowers who also did the bass for Walk on the Wild Side. wiki
