my $con = Audio::XMMSClient->new(...);
$con->connect or die $con->last_error;

my $res = $con->medialib_get_info( $some_song );
$res->wait;
my $value = $res->value;

##</code><code>##

my $con = Audio::XMMSClient::Sync->new(...);
$con->connect or die $con->last_error;

my $value = $con->medialib_get_info( $some_song );