As Mike stated it is very hard to keep a band going long term and especially keep them relevant which is where I would diverge with Mike in giving any props to Aerosmith and the guys from Oz with the schoolboy pants that mum hasn't had to iron I would imagine in almost 50 years.

Staying relevant in any art form (musical or otherwise) has to be extremely difficult and thus gives a decided advantage to the likes of Coltrane, Cobain, Schubert, Plath and Pollock.

In terms of longevity, if nothing else, where rock music applies I too lean towards those that were once members of bands that meant a lot to me in their earliest guises and have gone on, in most cases in solo ventures, to make some pretty decent music if not earth-shattering. The Smiths first record, a touchstone for me, came out in 1984 and Morrissey's latest just released a few weeks ago has some pretty great moments on it. Likewise with the Jesus and Mary Chain's first album in 1985 and then 2008 saw Bobby Gillespie (the frontman for Primal Scream and drummer for the JAMC) release a decent if rather predictable record. Given the shape-shifting tendencies of Primal Scream over the last 20 years this predictability was entirely unpredictable.

Then there's David Byrne whose Talking Heads had their first great record 30 years ago and last year teamed up with Brian Eno to put out a pretty great album that sounded nothing like the heyday of Talking Heads. I have much more respect for an artist of this ilk than say the Cure or Depeche Mode, who I loved back in the day, but who are putting out albums after 30 years that are basically mining an already depleted pit.

As for The National vs The Walkmen non-debate it's very simple. The Walkmen rock and the National are a bunch of noodly wankers with a Nick Cave wanna-be lead singer.