diff --git a/libao/libao-async.rkt b/libao/libao-async.rkt
index 6dec88e..d62a52d 100644
--- a/libao/libao-async.rkt
+++ b/libao/libao-async.rkt
@@ -10,6 +10,7 @@
          ao_stop_async
          ao_play_async
          ao_is_at_second_async
+         ao_music_duration_async
          ao_bufsize_async
          ao_clear_async
          )
@@ -37,6 +38,7 @@
   (mutex
    device
    [at-second #:mutable]
+   [music-duration #:mutable]
    [bufsize #:mutable]
    queue-sem
    [queue #:mutable]
@@ -70,11 +72,13 @@
                     'done)]
                  [(eq? command 'play)
                   (let ((at-second (cadr elem))
-                        (buf-len (caddr elem))
-                        (buf (cadddr elem))
+                        (duration (caddr elem))
+                        (buf-len (caddrr elem))
+                        (buf (car (cddddr elem)))
                         )
                     (mutex-lock (ao-shm-mutex shm))
                     (set-ao-shm-at-second! shm at-second)
+                    (set-ao-shm-music-duration! shm duration)
                     (let ((bs (ao-shm-bufsize shm)))
                       (set-ao-shm-bufsize! shm (- bs buf-len)))
                     (mutex-unlock (ao-shm-mutex shm))
@@ -93,7 +97,7 @@
   )
 
 (define (ao-player ao_device)
-  (let ((shm (make-ao-shm (make-mutex) ao_device 0.0 0 (make-os-semaphore) (make-queue) #f)))
+  (let ((shm (make-ao-shm (make-mutex) ao_device 0.0 0.0 0 (make-os-semaphore) (make-queue) #f)))
     (ao-player* shm)
     shm
     )
@@ -109,7 +113,7 @@
 (define (ao_stop_async shm)
   (mutex-lock (ao-shm-mutex shm))
   (ao_clear_async* shm)
-  (enqueue! (ao-shm-queue shm) (list 'stop 0 #f #f))
+  (enqueue! (ao-shm-queue shm) (list 'stop 0 0 #f #f))
   (os-semaphore-post (ao-shm-queue-sem shm))
   (mutex-unlock (ao-shm-mutex shm))
   (let ((stopped (λ ()
@@ -128,8 +132,8 @@
     )
   )
 
-(define (ao_play_async shm at-second buf-size buf)
-  (let ((item (list 'play at-second buf-size buf)))
+(define (ao_play_async shm at-second music-duration buf-size buf)
+  (let ((item (list 'play at-second music-duration buf-size buf)))
     (mutex-lock (ao-shm-mutex shm))
     (let ((bs (ao-shm-bufsize shm)))
       (set-ao-shm-bufsize! shm (+ bs buf-size)))
@@ -143,6 +147,12 @@
     (mutex-unlock (ao-shm-mutex shm))
     at-second))
 
+(define (ao_music_duration_async shm)
+  (mutex-lock (ao-shm-mutex shm))
+  (let ((music-duration (ao-shm-music-duration shm)))
+    (mutex-unlock (ao-shm-mutex shm))
+    music-duration))
+
 (define (ao_bufsize_async shm)
   (mutex-lock (ao-shm-mutex shm))
   (let ((buf-size (ao-shm-bufsize shm)))