It is provided a method of producing a crystal of a nitride of a group 13 element in a melt by flux method. The method comprises providing a multi-phasic dispersion including dispersed and continuous phases, providing a non-solvent, combining the multi-phasic dispersion and the non-solvent, and selectively effecting migration of the dispersed phase into or through the non-solvent such that the microparticles are separated from the dispersion. Instructions, which are stored in memory, are executed by a processor to discriminate the one or more sounds, extract music features from the one or more sounds, analyze the music features using one or more databases, and obtain information regarding the music features based on the analysis.