The general rules of drum head tuning are:
The top head (batter side) is the pitch. Tightly tuned gives a higher pitch. Loosely tuned gives a lower pitch.
Bottom head (resonant head) is the sustain. A tight head gives a short sustain and a loose head gives a long sustain.
The pitch relationship has a remarkable impact. I, like Ghost Smoke, tune my resonant head higher than the batter head, usually a semitone to a tone higher, (smaller head smaller step, bigger head, bigger step.) This gives the pitch bend effect. By doing this, you lose the tone of the drum and it becomes more percussive. If you tune the bottom head to the same pitch, you end up with the purest tone. The problem with tuning drums to tones is what if the pitch of your toms are C,E,G, a triad which is what I hear sometimes. And lets say your guitar player tunes down a half step to Eb, then the whole guitar down and starts playing a guitar in the key of C. Well...to him he's in C but to your drum kit, he's in B which has 5 sharps. Now your toms are chromatically out of tune with the entire song. Furthermore, even if he plays in E or A which are common guitar keys, two of your perfectly tuned drums are still out.
If you want tones, get a timpani unless you want to tune your drums every song.