When I was growing up we were regularly exposed to classical music. There was nothing high-brow or pretentious about it, it was just that my parents enjoyed certain classical pieces and played them often, consequently we loved them too. I remember one of my brother's earliest words yelled from his car-seat being "Dvorak!". As he demanded to hear more of the New World Symphony.
(Not for nothing but my brother ended up being quite academically brilliant and musically talented.Also, good looking.)
I, like most earnest first time mothers of the time, totally bought into the Mozart Effect theory, and diligently exposed my first-born to classical music from the womb. (I also made him listen to his French, Russian, Chinese, German and Spanish tapes every single day as a baby), I would have totally scared myself if I knew myself back then.
My first-born is indeed brilliant, and seems reasonably musical, but so are my second, third and fourth born (and I am of course, completely un-biased), who as you might have guessed, did not have as rigorous an education courtesy the One Step Ahead catalogue. (I do seem to remember watching numbly as kid number 3 unraveled the language tapes so that I could have 2 minutes of peace).
My point is that exposing your kids to classical music when they are young, in an attempt to raise their IQ can't hurt, but there are other even more compelling reasons to do so. I remember as a teenager coming home from boarding school on the weekends. My sweet boyfriend at the time would often accompany me and both of us would find great respite and peace in the classical music only policy my parents had on Sundays. It was such a pleasant break from the non-stop barrage of rock/pop/rap/reggae/metal/house/etc/etc music we were exposed to all week long (all at the same time!).
I still tend to play classical music to the exclusion of anything else when I am in a particularly stressful phase of life.
Having some sort of familiarity and appreciation for classical music can enrich a child's life for the rest of their lives. It opens a whole new world to them. I think it's really helpful to expose them to it early, when they have no pre-conceived ideas about it, and can grow to love it on their own terms in a very real and uncontrived way.
I'm not a music teacher or educator, so take my comments for what they are are worth, but something I enjoy doing with my youngest (aged four) who is still my trusty sidekick for most of the day, is to tune into NPR as we are driving, and then have him tell me what is going on in the music. He enthusiastically weaves all sorts of tales as the piece plays. There is inevitably a prince, princess and evil witch involved. He listens really carefully for changes in the music and his story lines are always appropriate to the music. He seems to understand the change in emotion and mood when a minor key comes along, and the different personalities different instruments can have. He recently added a horse into the mix, to what really was a very galloping portion of the music. I was quietly jubilant.
It's something we both enjoy, and a way for us to interact when we're in the car, while exposing him to something I hope he will develop a love and appreciation for. It's easy, and fun and natural and that works for me.