John Enwistle, one of the best technically, one of the most musical; and certainly given his body of work and it's significance, the greatest bassist in the history of rock (other than perhaps James Jamerson, who basically invented Rock and Roll and soul bass as we know it)... at the time 56 years old (we lost him two years later in 2002), delivering a virtuoso performance on "5:15" (from "the who" album "Quadrophenia"), without breaking a sweat.
Entwistle pioneered many of the techniques now considered standard in hard rock, progressive rock, and heavy metal bass playing, including: bi-amping, the use of high powered 8 speaker bass stacks (necessary to be heard clearly over the high energy drumming of Keith Moon - eventually he used two 200 watt amps, each feeding two 4x10 or 4x12 cabinets, or sometimes four 2x15 cabinets, for a total of 16 driven speakers), the use of feedback, tapping, and harmonics as a musical element for the bass, the use of effects, and the general "lead bass" style.
It is generally thought that his bass solo on "My Generation" is if not the first, certainly one of the first bass solos in recorded rock music (they were not unknown when bands were playing live, but they rarely made it onto records, and almost never onto rock records; as they were considered to be more of a "modern jazz" type thing).
Many of what people think are classic Pete Townshend guitar riffs, and even solos, are in fact Entwistles bass work; especially the intros to many classic who songs.
Entwistle is yet another reason why I believe "The Who" were the BEST (not the greatest, that's clearly "The Beatles") band of their time (not that Paul McCartney isn't a very good -and very innovative- bass player. He is.. and as far as I'm concerned he was the far greater talent than Lennon in the Beatles).
Here's the entire 2-1/2 hour live concert from 2000 (later released as the album "Live at the Royal Albert hall"), that the bass solo from "5:15" above is pulled:
And yes, by then, Townshend had clearly lost too much of "it" to keep on the way he was trying to. I saw them in 1989 for their 25th anniversary of Tommy "The Kids are Alright" tour, and they just utterly blew me away.
In between, somehow, Townshend blew out his voice entirely, and seemed to have lost his ability to either keep time, or play on key.
But, Entwistle, Daltrey, and their drummer (more in a moment) were really on for that tour (Daltrey has since lost too much of "it" to keep going as well).
Oh and the drummer for that concert happens to be Zak Starkey, the son of one Sir Richard Starkey, better known as Ringo Starr.
Starkey has been the drummer for "The Who" since 1996 (much as Jason Bonham has been for the various Jimmy Page projects, including the Led Zeppeling reunion). Appropriate, since it was actually Keith Moon who taught him to play drums (and rather well at that).