四个半音,或者说5个白加黑的键
let sound = 'piano: o3 c e' $`alda play -c ${sound}`
c 和之后的 4 个半音(或者说总共5个白加黑的键)分别为
let sound = 'piano: o3 c c+ d d+ e' $`alda play -c ${sound}`