Ok, Raedwulf: no, you can't generalise about GPs as they are such a mixed bunch: I would actually agree with most of what you said in your second paragraph (the bits I could understand!): but I'll go back to what I called "internal referrals" within the practice: you turn up with X problem: "Oh, not my province - see Dr Y who knows much more about that - might save you a visit to hospital and you'll get it sorted much sooner - he/she has done hundreds of these procedures successfully. If we send you to hospital you'll be waiting 3 months at least and might only see the SHO who has only done this procedure twice".
And yes, Pseudonymous, there are specialists out there who are appointed to symphony orchestras and the like to advise on joint problems resulting from playing positions, ENT consultants who advise professional singers on voice problems, etc. There is always a physiotherapist or osteopath available at Edinburgh Harp Festival to advise/treat, musculo-skeletal problems in harpists: not sure whether that's due to the playing position or just effects of lugging those heavy beasts about!