File Extension SAT File Format SAdT Music Composer song file SAT stands for SAdT Music Composer song file. This was last updated in March 2012 By Margaret Rouse Browse File Extensions Alphabetically: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # Ask a Question. Find an Answer. Ask your peers a question about this file extension. Ask a Question Spotify goes Social Google Music Search is here! Sort of. Apple to Start Streaming from iTunes?