It's limited: the ways in which an artist can grow old--or empirically it at least seems that way. One would think we have a veritable wealth of evidence in musical careers but really, it is surprising just how many throw in the towel. There comes a point that the shitty day job to support the anemic artistic career (that frequently requires long hours of low-grade travel and sleeping on people's floors) all begins to lose its allure. I wonder why?
By-and-large the ones left ascended to at least a baseline of 'cult' appeal. Even though I could rattle of a list of names starting at the Rolling Stones and Neil Young, passing through Morrissey and Echo and the Bunnymen and ending at the Orb and O Yuki Conjugate, I still find most of these artists falling into about three categories.
Constant innovation seems unsustainable. Every artist known for so-called innovation eventually falls behind the people expanding on their own achievements. Brian Eno might have the greatest track-record of the seventies. Add to his revered career as an ambient music pioneer his highly influential pop career, his moonlighting with various amazing artists (David Bowie, Robert Wyatt, John Cale) and producing startling upstarts (Devo, Ultravox, DNA), and you have a map of half of what is considered good and worthy from that decade. All this, and his last few albums have been... quaint... dated, even.
Many artists try and retreat to what once made them popular--a sort of returning to the well. It is often critically and commercially applauded: they are essentially giving fans exactly what they want. Of course the test of time is not so kind: late-period retreads by U2 and the Cure are never in the list of landmarks when their works are assessed. At this point it can be seen that the artists have settled into their careers as an act of labor, not creation.
As a side note: I still like bands to ape the sound of older artists I love--I just no longer seem to like those same artists to sound like themselves (or more accurately, like their old selves, which I suppose is exactly my point).
The most successful attempt at a late career maneuver I have witnessed is when the artist settles into an unfussy but unromantic sound. It separates them from the idea of innovation, or even keeping up with innovations of others. As a style, it often references their own past without reproducing it, sparing them being labeled a rehash.
While Bob Dylan may be the most famous example, with his lean and efficient, workman-like records of the 2000s, the best example I have heard is in fact Wire. I guess, in a way, it makes sense. Wire was never short on confounding expectations. They were principle in showing the way from punk to post-punk then promptly disbanded. They reformed before it could be called a reunion to release artful electronic rock then disbanded again before it got embarrassing. They did a reunion tour, which in-itself was surprising, then they started recording new music--and did so with energy and grace.
Their new sound is streamlined and metronomic but not in the same way their early punk records were. It's electronically enhanced but never really electronic pop. It's rarely overly aggressive and never too saccharine. Most of all, it seems to be outside any trend in music. This new-century Wire is a casual extension of their history, the sound of a band with a style its own but nothing to prove. Of course its also sounds like the result of a band that likes their jobs. They have seemingly found a balance. Next thing you know, they'll break up (again).