In music, as in life, all good things must come to an end, which helps explain why even the most lucrative partnerships tend to flame out before too long.

Think about it: For every Jagger and Richards who have managed to defy the odds, there's a Simon and Garfunkel, or a Morrissey and Marr, or even a Lennon and McCartney who have had to part company amid some degree of acrimony.

That's why it's something of a minor miracle that Jim Cuddy and Greg Keelor -- the principal songwriters behind Canadian roots-rock sensations Blue Rodeo -- have managed to maintain not only a productive artistic relationship, but also a genuine friendship for all these decades.

"This can be a crazy business ... so in all that big stew, it's nice to have someone you have a shared experience with," says Keelor from Edmonton, where Blue Rodeo is gearing up for the second show of its current cross-Canada tour.

"Besides, Jim and I are like family -- we're not like Simon and Garfunkel or the Everly Brothers ... you know, we've actually performed shows with both those acts, and in both cases, they arrived in separate cars, had separate dressing rooms and didn't even speak to each other until they were on stage."

That's definitely not the case with Keelor and Cuddy, who've known each other since high school, spent their "nomadic" post-grad years roaming Alberta in a bus together, started up their first band The HiFis in 1977, and still spend Christmas vacations with each other's families.

The sustained camaraderie goes a long way towards explaining how it is that Blue Rodeo has remained such a viable presence on the Canrock scene, and how it is their songs have become such an undeniable facet of the Canadian experience in general.

Not that Keelor spends too much time pondering his status as a cultural touchstone.

"It's always funny to hear that stuff, that you're part of the fabric of someone's life, or whatever," says Keelor, considered by some to be the edgier yin to Cuddy's more pure-voiced yang.

"I used to read the fan mail, but I had to stop, because it just got too heavy. The worst was this lady who wrote about how her brother's car had gone off the road and he was killed, and there was a Blue Rodeo tape playing in his car at the time. I didn't need to hear that you know? It gives you the bugaboos.

"But as a touring musician, it is nice when people know the words, And it's nice when you're in the grocery store and someone says, 'Lost Together was my wedding song.' "

Speaking of history, the Blue Rodeo boys got back to their -- ahem -- roots earlier this year, when they did some busking gigs throughout Toronto as part of the publicity tour for their recently released disc Small Miracles.

"Yeah, we liked it so much, the first half of the (current) tour is us playing ... very stripped-down and acoustic version of our songs," says Keelor.

In addition to the makeshift hootenanny, local audiences will be excited to see former Winnipeg resident Luke Doucet warming up for the band. Doucet -- a Blue Rodeo compatriot since his early-'90s days with Sarah McLachlan's band -- recently accompanied the gang on a tour of the U.S., along with Ron Sexsmith and Justin Rutledge.

In fact, Keelor (who released his last solo album Aphrodite Rose in 2006, around the same time Cuddy put out his own solo disc, The Light That Guides You Home) recently turned in a particularly apt cameo on an album by Doucet's wife, Melissa McClelland.

"She has a song about when she was young, her and her boyfriend would make out underneath the Skyway Bridge," Keelor laughs. "The song they'd listen to while they made out was Lost Together."

So far, both the new album and the tour have been drawing the sort of reaction Blue Rodeo has come to expect, with most notices punctuated by words like "reliable," "workmanlike," and "consistent."

Not that there's anything wrong with that, of course.

"I think when you've been around as long as us, you're sort of taken for granted a bit," says Keelor. "I just feel like I have such an enjoyable musical life -- the Blue Rodeo thing is great, we're a popular band and we can work."

"How I'm perceived by the rest of the world isn't that important. But that said, I'm glad we're on this side of the ledger."