The 13 was the "standard" size tom during the 60's-70's. Prior to that it was the 12. Prior to that it was the 13. After the 70's it was the 14. After that it was the 12. Go figure. This snapshot in time that we find ourselves in, we see the 12 being the "standard" tom to which others are tuned and measured. The 15 has always been the poor stepchild. They make a wonderful step down from the 13. As you become more musical in your approach to the large kit setup, you will discover that running contiguous tom fills is not necessarily the best approach. You will find the better blending of the 12/14 match and the 13/15 match. You will begin skipping toms in your runs so as to maximize step tones.

As far as the cymbals, the odd sizes are wonderful! The 15 17 and 21 are slightly larger than the 14 16 20 even sizes sizes. They have a slightly larger presence and speak slower than their smaller counterparts. The 21 in particular is a GREAT alternative to the 20. It allows you to lay in to it a bit more (all things being equal). You should seek out the 19, also. Absolutely brilliant size for a cymbal. WAY better feel than the 18. The even sizes have always felt like the uptight cymbals while the odd sizes are the laid back easy going cymbals. That's how I view them.

Hmmm, that is an interesting explanation.

In oneof my bands I play with a 15" crash - great for fast work, but just that bit more presence than a 14" . I ordered it on a whim because it was cheap, but I'll probably stick with a 15 in that position now!! As for drum sizes I have a friend who, when he was endorsed ordered an odd size kit just to be akward!