My Robot Drummer...

DIY Beats

Gene Boggs

Epistemologist at-large

MIDI::Simple::Drummer

1. It's on CPAN and will install on any machine.

2. It only depends on MIDI-Perl, which depends on nothing but Perl itself!

Static, not dynamic. Sorry.

• This package renders a .mid file. It does not magically interact with you... yet.
• Real-time MIDI is different on every OS and no-one seems to care enough to make it happen in reality, on the computer.

Why?

• I hate the metronome.
• The metronome does not help you stay in time when you are playing exactly on the beat.
• Metronomes go on forever, which is not real. Songs have an end.
• Drummers cue your place in the song.
• I miss my virtuoso drummer and teacher, who mixes it up and keeps it fresh.

What Song Do You Think This Is?

Back In Black!

Beats

• This drummer is made for straight-time, straight-ahead beats like AC/DC.
• Pretty soon, I'll make a jazz knowledge base and swing it.

The General MIDI Kit

The GMK is pretty feeble but works just fine and is part of every machine.

• Drums: Acoustic Snare, Acoustic Bass Drum, Bass Drum 1, High, Hi-Mid, Low-Mid, Low, High Floor & Low Floor toms
• Cymbals: Closed, Open, Pedal Hi-Hat, Chinese, Crash 1, Crash 2, Splash, Ride Bell, Ride & Ride 2 cymbals
• Miscelaneous other instruments like Claves and Congos.

The GMK does not encompass Neil Peart's kit

Drag the .mid to your favorite sequencer

And fiddle about with the bits. Every sequencer has better patches than the GMK.

Let's Get This Party Started!

• The essential methods are briefly documented in MIDI::Simple::Drummer.
• But we want to extend the capabilities of our drummer!
• But first, let's check out the essential bits...

The Kit

• The kit is just a hash-ref of internal method names, like

  {kick => 'Acoustic Bass Drum',} 

• You can add, subtract or modify anything in the set.
• That is as easy as saying,

  $d->kit(kick => 'Cowbell');
  # or just
  $d->kick('Cowbell'); 

Patterns and grooves, fills and frilly bits

• Patterns and fills are just a hash-ref of beat names (currently numbers).
• Use The Source, Luke.

Example rock pattern and fill

5 => sub { # "Syncopated beat 2" en c-hh. qn k1,3,3&,4&. qn s2,4.
 my $self = shift;
 my %args = @_;
 for my $beat (1 .. $self->beats) {
  $self->note($self->EIGHTH,
    $self->backbeat_rhythm(%args, -beat => $beat));
  $self->note($self->EIGHTH,
    ($beat == 3 || $beat == 4
      ? ($self->kick, $self->tick) : $self->tick));
 }
},
'1 fill' => sub {
 my $self = shift;
 $self->note($self->QUARTER, $self->snare) for 0 .. 1;
 $self->note($self->EIGHTH, $self->snare)  for 0 .. 3;
}, 

Some Dynamics

• Intelligently modulate dynamics.
• Add nuance methods like accent and crescendo, legato, etc.

#
sub accent { # Pump up the [dynamics] (default Volume)!
 my $self = shift;
 $self->{-accent} = shift if @_;
 my $accent = $self->{-accent} + $self->volume;
 $accent = $MIDI::Simple::Volume{fff} # Max MIDI is fff
   if $accent > $MIDI::Simple::Volume{fff};
 return $accent;
} 

The Ugly Setup

#
sub _setup { # Where's my Roadies, Man?
 my $self = shift;
 $self->{-score} ||= MIDI::Simple->new_score;
 $self->{-score}->noop('c'.$self->{-channel}, 'V'.$self->{-volume});
 $self->{-score}->set_tempo(int(60_000_000 / $self->{-bpm}));
 $self->{-kit} ||= $self->_default_kit();
 $self->{-patterns} ||= $self->_default_patterns();
 return $self;
} 

The Lovely, Flexible Syntax

#
use MIDI::Simple::Drummer::Rock;
my $d = MIDI::Simple::Drummer::Rock->new();
$d->count_in;
$d->patterns('end fill' => \&fin);
$d->fill(-name => 'end');
$d->write;
sub fin {
 my $d = shift;
 $d->note('en', $d->crash) for 1 .. 2;
 $d->note('sn', $d->snare) for 0 .. 2;
 $d->rest('sn');
 $d->note('en', $d->kick) for 1 .. 2;
 $d->note('en', $d->strike('Splash Cymbal', $d->name_of('kick')));
} 

Any sufficiently advanced drummer...

• ...will probably still sound like a robot.
• But there is hope! There is AI. And anyway, thare are other "humanized" machines out there already.
• And frankly, some people just want to get away from Humans and their feeble "capabilities" and experiment with The Future.

The Future[TM]

• Drummers that do crazy, combinatorial things. (Stunt drumming, if you will.)

• Drummers that systematically run through experimental beat patterns.

• Evolutionary drummers. Duh.

• Markov chains and stochastic functions.

• Use this (or its methods) as a basis for modern drummers, who use Moose, etc.

• Real-time interaction? That is, live jamming. This is a sticky wicket...

To do

• Multi-track!

• Comprehend time signature and keep a running clock to know where we are in time, at all times.

• It don't mean a thing if it ain't got that swing. That is, make a MIDI::Simple::Drummer::Jazz package.

• Add 32nd and 64th durations to the %MIDI::Simple::Length hash.

• Import patterns via the read_score() method in MIDI::Simple?

• Leverage the from_drum_tab() method in MIDI::Tab?

See also

• The eg/* and t/* files, that come with the distribution.
• Style package(s) like MIDI::Simple::Drummer::Rock.