antique bandolim banjo banjolin bill monroe bluegrass book bouzouki bowlback buying calace case cbom chords choro chris thile classical music dudu maia eastman electric electric mandolin fiddle fiddle tune flatiron fretboard gibson harmony ian coury identify jazz jazz mandolin kentucky lessons loar f5 luthier mandocello mandola mandolin mandolin orchestra mandolin sheet music mandolin technique math rock mattcbruno neck joint new music northfield octave mandolin picks pickup pmo repair repair advice requested ronnie mccoury scottish sheet music stradolin strap strap button strings tabs technique theory thile transcription truss rod tuning value estimation vinaccia vintage weber