0 ACLEAR()

0 OP = AUNIT(A_OUTPUT,0,A_ENVFIXED)
0 OUTOP = OP

0 LOOP I, 500
0 OP = AUNIT(OP,,A_ENVFIXED)
0 AFILPOINT(OP, A_FILFW, 0, 0)
0 AFILPOINT(OP, A_FILFW, 15, 1024)
0 LOOPEND

0 AADDOUT(  1, A_OUTPUT, 100)
0 AADDOUT( 50, A_OUTPUT, 100)
0 AADDOUT(100, A_OUTPUT, 300)
0 AADDOUT(150, A_OUTPUT, 200)
0 AADDOUT(200, A_OUTPUT, 100)
0 AADDOUT(250, A_OUTPUT, 400)
0 AADDOUT(300, A_OUTPUT, 100)
0 AADDOUT(350, A_OUTPUT, 300)
0 AADDOUT(400, A_OUTPUT, 100)
0 AADDOUT(450, A_OUTPUT, 200)
0 AADDOUT(500, A_OUTPUT, 500)

# sound source

0 O1 = AUNIT(OP, 256, A_ENVFIXED)
0 O2 = AUNIT(OP, 256, A_ENVFIXED)
0 O3 = AUNIT(OP, 256, A_ENVFIXED)
0 O4 = AUNIT(OP, 256, A_ENVFIXED)

0 AOSC(O1,  800, 1024  ,, A_SQUARE)
0 AOSC(O2,  700, 1024+3,, A_SQUARE)
0 AOSC(O3, 1000, 1024*2,, A_SQUARE)
0 AOSC(O4,  600, 1024*3,, A_SQUARE)

0 AADDOUT(O1, O1, 500)
0 AADDOUT(O2, O2, 600)
0 AADDOUT(O3, O3, 400)
0 AADDOUT(O4, O4, 300)

0 AENVPOINT(O1,,   0,   0)
0 AENVPOINT(O1,, 200,1000)
0 AENVPOINT(O1,, 700,1000)
0 AENVPOINT(O1,,1000,   0)

0 AENVPOINT(O2,,   0,   0)
0 AENVPOINT(O2,, 250,1000)
0 AENVPOINT(O2,, 600,1000)
0 AENVPOINT(O2,,1000,   0)

0 AENVPOINT(O3,,   0,   0)
0 AENVPOINT(O3,, 300,1000)
0 AENVPOINT(O3,, 500,1000)
0 AENVPOINT(O3,,1000,   0)

0 AENVPOINT(O4,,   0,   0)
0 AENVPOINT(O4,, 350,1000)
0 AENVPOINT(O4,, 450,1000)
0 AENVPOINT(O4,,1000,   0)

0 APLAY("T60CDEC1",,, "concert-hall.wav")
