3 M in a B = rub-a-dub dub ... no, that's in a Tub, not a Bathtub
4 H of the A = horsemen
4 P of the C = points of the compass?
12 on a J = (haven't a clue)
12 D of C : days of Christmas
13 = B D : the so-called Nadia (with a British accent) of Boulanger (with a French accent)
14 S of the C: is that Stations of the Cross?
15 M on a D M C: Y H H and a B of R
16 T and WDY G: (credit to Ernie Ford, please)
24 = H T T = (no clue here either)

How about

30 S over T
7 B for 7 B
7 W of the A W
7 H of R
3 C in the F