Listening to the original played loud on full-range speakers, there
is a bass guitar playing a four-to-the bar bass line but it is very low in the mix and the bass drum also plays four-to-the-bar (with full front skin, hence a 'boom' rather than a 'thud') so the two are virtually one sound most of the time.
The lead line (played, I am reliably informed by Jim N., on a Jaguar tuned down to D) is complimented by the second guitar part (was it also Jim who told me that this was played by Big Jim Sullivan?). It's this second guitar part that is often missing when the number is played live and the tune loses a lot when it is not there.
George Geddes wrote: I have heard it done with a bass as a lead instrument, but it doesn't really work IMHO. It should be played on a guitar!
George
For anyone with a copy of the Pipeline 2004 Convention DVD, Ted Harvey of The Packabeats plays
Diamonds on his bass guitar in the key of E (rather than the D of the original), but Ted plays it around the 5th fret ie in the same register that it would be on a guitar. Ted then adds a touch of flanger to make the sound swirl a little and Malcolm on guitar plays a combination of chords and second lead phrases. Sounds good to me!
Ray L