/playsound plays no sound -- WAI due to sound name change

When I ran a playsound command (both in chat and in a command block) on this snapshot, it made no noise. However, ingame sounds still worked fine. Then, when I switched back to 15w42a, it did make a noise once I ran the same command.

Command to reproduce:

/playsound note.harp @p

EDIT: Bentroen discovered that some sounds still work when run by a playsound command. For instance:

/playsound record.cat @p

This command (at least in 15w43b) will play the correct sound, and this may be caused by it not having any subtitle whereas other sounds do.

EDIT 2: Dlawso the Really Lucky Rabbit and user-f2760 made me realize that this isn't a bug - it's an intended feature. Grum had to modify a lot of the sound file names to distinguish different sounds for subtitles, which ended up breaking some playsound commands we all were used to. We just need to adjust to the new sound names, found in the attatched sounds.json file (thanks to whoever attatched it!).