: id3v2? ( path -- ? )
    "ID3" head? ;

: id3v1? ( path -- ? )
    128 tail-slice* "TAG" head? ;

: supported-version? ( seq -- ? )
    [ { 4 } head? ] [ { 3 } head? ] bi or ;

: id3stuff ( path -- mapped-file ? )
    [
        {
            { [ dup id3v2? ] [ 3 tail-slice supported-version? ] }
            { [ dup id3v1? ] [ "id3v1" ] }
            [ drop "none" ]
        } cond
    ] with-mapped-uchar-file ;