fetchrow_arrayref() returns you an array reference, so you should use it in a way like this:
while (my $track_ref = $sth->fetchrow_arrayref ()) {
print $$track_ref[0]; # This prints the first field
print $$track_ref[1]; # This prints the second field
# ...and so on
}
If you plan to use this method, it's a good practice to avoid
SELECT *, and specify in the query all the fields in the order you expect them to be. It works even with the first syntax, however you're going to need to adjust your code if for some reason you recreate your table with a different field order or with additional fields inserted in the middle.
Michele.