Tonic Triad Drill with Letters Theory Things   William Wieland
Each letter followed by a comma is sung as a quarter note, all others are eighth notes. This exercise can be sung as a canon.

c
a a  a a.
e e  e ee,      
 c  c cc,      
aa,      

cc,      
 a  a aa,      
e e  e ee,      
c c  c 
aa.