There should be some music in H/M, so I have thought of some instruments to craft and play!
The trumpet produces high notes. It is crafted with Gold or Iron ingots, Gold/Iron Nuggets and 3 Buttons, like the following:
I = Gold/Iron Ingot N = Gold/Iron Nugget B = Button B B B I I I N N N
The tuba produces the lowest notes and is crafted like this: A gold block, with two gold ingots one down, the other down diagonal.
One could also craft it using a Iron Block and two Iron Ingots, but this would cause the notes to jar a little bit. Gold gives the best results.
B= Gold/Iron Block I= Gold/Iron Ingot A= Air (nothing) A I A A B A A A I
The drum produces notes inbetween the tuba and trumbet, and is used to keep a beat. It is crafted like the following:
L=Leather W=Wood A=Air (nothing) W L W W A W W W W
The flute is just three iron nuggets in a straight line, the notes are very high, but will often echo across the hills, producing a sometimes haunting tune.
Often considered sad is tune from the humble Bagpipe. It is best played in an extreme hills biome.
L=Leather S=Stick L L L L L L S S S
Add more as you feel!