ive been writing my own music for about 2 years now..... i kinda found a little trick to harmonize over a lead or rythem if its single notes like if you are using a keyboard.... if your using tabs like most ppl do then all you do is write your lead part down..... and whatever numbers you got on your lead add or subtract 7...and go 1 string up or down depending on what you need..... i dunno why but for me it sounds pretty cool.....any one have any other tricks or formulas to harmonizing???