7 -8 8 8 -8 -8 7 Thirty days has September 8 -9 9 9 -9 -9 8 April, June and November. 7 7 7 7 6 -7 7 All the rest have thirty-one, 7 7 6 6 6 6 6 7 Saving February alone, 9 -9 8 -8 7 -7 -6 -7 Which has twenty-eight, rain or shine. 6 6 6 9 9 9 7 And on leap years, twenty-nine. This can be played in the 4 - 8 range with good results. Some problems on the -6 equivalent in the lower octave.