However, you are doing too much work:

...

# load address book entries
my $sth = $dbh->prepare('SELECT * FROM addressbook');
$sth->execute();

my %data = map {$_->{last} => $_} @{$sth->fetchall_arrayref({})};
print Dumper \%data;
[download]

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)