The Richard Thompson Band Live at Celtic Connections might beg the question: is Richard Thompson's music really Celtic? That question might in turn beg an even more impertinent one: what exactly is Celtic Music? Modern day dilettantes might only know of Celtic Music through the ersatz PBS pledge week phenomenon of Celtic Woman. (Note to these folks: even with Irish tin whistle and fiddle included in the instrumentation, "My Heart Will Go On" from Titanic is not authentic Celtic music.) Other, more worldly and experienced, types might mention everyone from The Chieftains to Clannad to Alan Stivell to Capercaillie to Deanta to Aine Minogue to Anuna to The Corrs to, yes, U2 in even a cursory overview of this seemingly indefinable genre (if genre is even the right word for something so obviously far reaching and varied).