“I read in a popular book on recording recently that you should tune your drums to the key of the song. I can see where this might make sense, but it seems like quite a bit of trouble to retune for each song in an album project. Do people really do this?”
This is largely personal preference. It certainly can make a positive difference to tune drums this way, though that depends a lot on how the drums sound and how they are used in the recording. Personally I’ve rarely gone this route. I’ve usually found it more productive to get the drums sounding as good as they can by themselves without much regard to the specific pitches of the toms.
The most important things for a good drum sound are: 1) Good sounding drums, which means you need a good kit, with relatively new (not dead) heads; 2) Proper tuning in terms of optimizing the sound of the individual drums (this is a real art form); 3) a good sounding room; 4) good/appropriate microphones and preamps; 5) proper mic placement (another art form); 6) and finally, a good drummer. This last point cannot be over emphasized. A good drummer can truly make all the difference in the world in how a kit sounds. When you have these things all in place you’ll be amazed at how easy it is to get great sounds.
Anything beyond that is personal preference for aesthetics. If you’re working on a piece where there’s a lot of melodic tom-tom work then it’s almost surely worth the effort to work the tuning out so it makes sense in harmony with the song, especially if the toms are placed in the mix so they are easy to hear. If you happen to be going for a bright tom sound that will cut through the mix and stand out you may still want to tune for the key of the song. For a typical rock or pop drum sound, however, it’s more important to tune the drums so they sound their best, regardless of the pitches. Try to get a rough mix going during tracking so you can best hear how they sound in context with the other instruments. This way you can check your work and make sure you don’t have any problems or notes that are conflicting. Sometimes you will hear something wrong. That floor tom ring may really clash with that note the bass player holds at the end of the chorus, for example. You may have to go change the tuning of that drum enough to move it out of the way of the bass. It’s generally pretty easy to handle these issues on a case by case basis as this type of problem doesn’t crop up all that often.
Another decision you should make going in to a full length project is whether the drum sound needs to stay consistent all the way through. Not only will this help decide whether you can or should change tunings for each song, but also will dictate whether you should track them all during one extended session, as opposed to a new setup for each song. Once you’ve weighed all these factors you should be able to come up with a plan that will likely answer your question for you. Obviously the best way to know for yourself what different drum tunings do for the sound is to try it a few different ways. This is one of those things that if you take the time to go through it once you’ll gain a lot of knowledge (experience) you can carry with you and use for years.