Can't puzzle out how to play a note

.pl

#!/usr/bin/env perl

use v5.36;

use Data::Dumper::Compact qw(ddc);
use IO::Async::Timer::Periodic;
use IO::Async::Routine;
use IO::Async::Channel;
use IO::Async::Loop;
use Future::AsyncAwait;
use MIDI::RtMidi::FFI::Device;
use Time::HiRes qw/ gettimeofday tv_interval /;

my $port = shift || 'tempopad';

my $loop = IO::Async::Loop->new;
my $midi_ch = IO::Async::Channel->new;

my $midi_rtn = IO::Async::Routine->new(
    channels_out => [ $midi_ch ],
    code => sub {
        my $midi_in = MIDI::RtMidi::FFI::Device->new( type => 'in' );
        $midi_in->open_port_by_name(qr/\Q$port/i);

        $midi_in->set_callback_decoded(
            sub($ts, $msg, $data = undef) {
                # my $t0 = [ gettimeofday ];
                $midi_ch->send($msg);
            }
            # sub { print join("\n", ($_[0], $_[2]->@*)) }
        );

        sleep;
    }
);
$loop->add( $midi_rtn );

my $midi_out = RtMidiOut->new;
$midi_out->open_virtual_port('foo');
$midi_out->open_port_by_name(qr/fluid/i);

$SIG{TERM} = sub { $midi_rtn->kill('TERM') };

async sub process_midi_events {
    while ( my $event = await $midi_ch->recv ) {
        say ddc $event;
        # say "recv took " . tv_interval( $event->[0] ) . "s";
        # say "ts " . $event->[1] . "s";
        # say unpack 'H*', $event->[2];
        # $midi_out->note_on($message->[1], $note, $message->[3]);
    }
}

my $tick = 0;
$loop->add( IO::Async::Timer::Periodic->new(
    interval => 1,
    on_tick => sub { say "Tick " . $tick++; },
)->start );

$loop->await( process_midi_events );