notateTremolo :: RealFrac b => Maybe (TremoloT a) -> b -> (LyMusic -> LyMusic, b)
notateTremolo Nothing d                        = (id, d)
notateTremolo :: RealFrac b => Maybe (TremoloT a) -> b -> (LyMusic -> LyMusic, b)
notateTremolo Nothing d                        = (id, d)
notateTremolo Nothing d                        = (id, d)