Cambridge Aerospace Dictionary

Cambridge Aerospace Dictionary (2004), "This dictionary is an essential tool for people who must read and understand technical content regarding the aerospace industry and specific aircraft." I checked the terms 'musical,' and 'music,' but still none the wiser.

Musical: Musical Prefix to marking techniques denoting Oboe guidance (RAF 1943-45).
Music 1 Multiple signal classification. 2 Multi-spectral IRCM.
Music EW emissions, esp. jamming (colloq.).