To follow up on what davido said, if you're working with ID3V1 tags you can do something like this:

open FH, "<$mp3" or die "Could not open file $mp3\n";
             binmode FH;
             seek (FH, -128, 2);
             read (FH, $tag, 128);
             next if $tag !~ /^TAG/;
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This is using the fact that the ID3V1 tag has the word TAG at the begging of said tag. If you're working with ID3V2 tags, I'd look at using one of the Mp3 modules from CPAN.