#1
My theory teacher over the summer was telling me about tetra scales and I was wondering if they were just combining the first four notes of any two given scales?
myspace.com/soundsofmeta
#2
Hmmm
I only know of tetrachords. A tetra scale would just be an arpeggio of some chord.

The "Re-incarnation of Plato" Award 2009
(most intelligent)
The "Good Samaritan" Award 2009 (most helpful)

[font="Palatino Linotype
Who's Andy Timmons??