Hi Ben
I would second Art’s comment. Also, for what it’s worth, when approaching libraries I just send examples of what I think I do best (or what I think is my best stuff). That way, based on their response, I find out from the outset if the library is a good fit for what I think I do. The ‘auditioning’ process becomes a two way street in that manner – you can get a sense of what a particular library is about. That said, if there’s scope for sending a number of tracks, go for what you think are your strongest genres plus maybe a couple of other examples. Just my approach though…