Sulasol, The Finnish Amateur Musicians' Association
SULASOL - it sounds like music - and so it is. The abbreviation is formed from the names of three notes along the lines of the age-old Guidonian solmization method.
The original explanation for the abbreviation, however, holds a bit more meaning: it is an acronym based on "Suomen Laulajain ja Soittajain Liitto", The Finnish Amateur Musicians' Association.