What does "no matching signatures" mean?

[willochill]

My script keeps crashing, apparently there are "no matching signatures" to the function PlayMusic(string@&, const bool, const double, const uint, const uint). Here's the script, please help! (you really only need to look at the first few lines though I think)

void OnStart()
{
PlayMusic("amb_extra01", true, 0.75, 0, 0);
FadeOut(0);
AddTimer("TimerFirstLook", 3, "FirstLook");
SetPlayerActive(false);
SetPlayerCrouching(true);
FadePlayerRollTo(-90, 100, 100);
AddEntityCollideCallback("key_laboratory_1", "mansion_1", "UnlockFirstDoor", true, 1);
}

void FirstLook (string &in asTimer)
{
FadeIn(3);
AddTimer("TimerFadeOut01", 6, "FadeOut01");
AddTimer("TimerSecondLook", 12, "SecondLook");
}

void FadeOut01(string &in asTimer)
{
FadeOut(3);
}

void SecondLook(string &in asTimer)
{
FadeIn(3);
AddTimer("TimerLook_01", 3, "Look01");
AddTimer("TimerLook_02", 4.5, "Look02");
AddTimer("TimerLook_03", 5.5, "Look03");
AddTimer("TimerLookBack", 7.5, "LookBack");
}


void Look01(string &in asTimer)
{
StartPlayerLookAt("AreaLook01", 1, 1, "");
}

void Look02(string &in asTimer)
{
StopPlayerLookAt();
StartPlayerLookAt("AreaLook02", 1, 1, "");
}

void Look03(string &in asTimer)
{
StopPlayerLookAt();
StartPlayerLookAt("AreaLook03", 1, 1, "");
}

void LookBack(string &in asTimer)
{
StopPlayerLookAt();
StartPlayerLookAt("AreaLookBack", 1, 1, "");
FadeOut(3);
AddTimer("TimerGetUp", 5, "GetUp");
}

void GetUp(string &in asTimer)
{
StopPlayerLookAt();
FadeIn(3);
AddTimer("TimerTurnHead", 3, "TurnHead");
AddTimer("TimerActivatePlayer", 6, "ActivatePlayer");
}

void TurnHead(string &in asTimer)
{
FadePlayerRollTo(0, 80, 90);
}

void ActivatePlayer(string &in asTimer)
{
SetPlayerActive(true);
}

void UnlockFirstDoor(string &in asParent, string &in asChild, int alState)
{
SetSwingDoorLocked("mansion_1", false, false);
}

void OnEnter()
{
}

void OnLeave()
{
}