by ear

• He is bind , but he can play many beautiful songs by ear
  他是个盲人，但他能凭记忆演奏许多动听的歌曲。
• John plays the violin by ear
  约翰完全靠声音弹奏小提琴。
• Ps : we should have plan in learning english , don ' t play it by ear
  我们学习英语要有计划,不要临急抱佛脚
• John plays the trumpet by ear
  约翰完全靠声音弹奏喇叭。
• John plays the guitar by ear
  约翰完全靠声音弹奏吉他。
• Not really . i played it by ear . i ' m lucky it turned out ok
  （没有。我随兴之所至。幸运的是结果还不错。 ）
• John plays the piano by ear
  约翰完全靠声音弹奏钢琴。
• Just wait and see . let s play it by ear
  只好等着看喽
• I haven ' t decided what to say when he comes ; i ' ll play it by ear
  他来时我不知道该说什么,到时候随机应变吧。
• I haven ' t decided what to say when he comes ; i ' ll play it by ear
  我还没决定他来时要说什么，到时随机应变吧。