It will be shown here that there are differential operators E, F and H = [E, F ] for each n ≥ 1, acting on Diagonal Harmonics, yielding that DH n is a representation of sl[2] (see [3] Chapter 3). Our main effort here is to use sl[2] theory to predict a basis for the Diagonal Harmonic Alternants, DHA n . It can be shown that the irreducible representations sl[2] are all of the form P, EP, E 2 P, • • • , E k P , with F P = 0 and E k+1 P = 0. The polynomial P is known to be called a "String Starter". From sl[2] theory it follows that DHA n is a direct sum of strings. Our main result so far is a formula for the number of string starters. A recent paper by Carlsson and Oblomkov (see [2]) constructs a basis for the space of Diagonal Coinvariants by Algebraic Geometrical tools. It would be interesting to see if any our results can be derived from theirs.