Originally Posted by
PollyCymru
As I understand it, the main reason for using hide glue in Musical Instruments is that it gives great strength but should the instrument sustain damage, the glue will break before the wood. This ensures that the wood of the instrument is less likely to be damaged, but the joint can easily be repaired. The glue works best when it is thin, unlike other glues where thicker is better. Otherwise you could just use any woodworking glue - but you wouldn't be able to repair any damage without further damage to the instrument.
This is precisely why hide glue is used, what good is an instrument which breaks in the wood rather than at the joint? It can't be repaired and is no use to anyone as a bunch of splinters ;)