As a rock musician, unless you start a successful recording career with your very first band (which is a mighty rare occurence), you will probably log a lot of hours learning and performing cover tunes, a.k.a. popular, famous tunes of the day or of the past.  This is generally a good and healthy thing, in my book. You can learn tonnes about techniques, tone, theory, effects, multi-tracking, arrangement, production, artistic quirks & character, and on and on and on. It's also a very effective way of training your ear to discern pitches, chord progressions, rhythms - you get the idea. As an added bonus, well-known tunes go over better with most music audiences than unknown tunes. As a result, a good cover band in a town like Vancouver can generally find gigs that pay right off the bat. A band that performs all its own music (a.k.a. 'originals') tends to have a much longer, harder struggle getting to the point of making a living. On the other hand, a well-established original act trumps a well-established cover band in terms of prestige, if not always income (there's a pretty wide variation from one act to the next). A lot of working musicians soon lose interest in playing in originals acts, as it seems a good way to starve - and often it is. Finding a receptive audience can also be a bit more of a challenge for an originals act...but if not for the originals, there'd be nothing for all the other musicians to cover - and there'd be no new music.
I've been in covers and originals acts for almost as long as I've been playing guitar, and thoroughly enjoy both - but I've always seen cover tunes as a means to an end, whereas originals were the end itself. Both my bandmates currently play in busy cover bands - Curtis in Full Moon, Trevor in Bang!, to name just one each - but the three of us seem hopelessly addicted to the original band experience (Trevor has his own solo project, in fact). I suppose I'll keep writing em for as long as I have things on my mind that don't translate well into conversation.
On March 25, the Mike Luno Band will flirty with the flipside - we'll be playing a night of about 80% cover tunes. It's fun, it promotes the band and it helps pay the bills...but is it actually MLB? I must say I've been wrestling with this issue a little lately, pondering an alternate band name for the mostly-covers nights (hey, it worked for the Odds) - but the jury's still out. It may depend on how busy we get with which repertoire. Hey, if you have an opinion on the subject, I'm all eyes.
In the meantime, perhaps we'll see you on the 25th and you can tell me what you think in person. Just don't ask us to play Brown Eyed Girl.