AT&T 6300 Programmer's Manual page 400

PLAY
Statement
Tn
MF
MB
MN
ML
MS
X variable
7-244
Sets the "tempo", or number of quarter notes, in one minute.
The n parameter ranges from 32 to 255, with a default value
of 120.
Sets Music Foreground. Music (PLAY statement) and
SOUND are to run in Foreground. Each successive note does
not start until the preceding note has finished. Music
foreground is the default setting.
Sets Music Background. Music (PLAY statement) and
SOUND are to run in Background. The GWBASIC program
continues as music plays in the "background." Up to 32
notes (or rests) can be played in the background at a time.
Sets "music normal", so that each note will play
7/8
of the
time determined by length (L).
Sets "music legato", so that each note will play the full
period set by length (L).
Sets "music staccato", so that each note will play 3/4 of the
time set by length (L).
Executes the specified variable string.