IRMAS instrument tagging is not parsed correctly

[GCPhillips]

Some of the IRMAS training files do not contain a genre tag at the end of the file name, and instead is an instrument tag. For example, if the training track with id 0001__1 is loaded, the genre will be cla and instruments will only contain cel, even though both are instruments and there is no genre tag:

In the code, a check could be performed to see if the parsed out string inside the brackets is in INST_DICT.