Simple ruby midi file player

gistfile1.rb

require 'pp'
require "unimidi"
require 'midilib/sequence'

# Prompts the user to select a midi output
# Sends some arpeggiated chords to the output
output = UniMIDI::Output.gets

begin
# Create a new, empty sequence.
seq = MIDI::Sequence.new()

# Read the contents of a MIDI file into the sequence.
File.open(ARGV[0], 'rb') { | file |
    seq.read(file)    
}

play_track=MIDI::Track.new(seq)

seq.each { | track |
  puts track.name
  play_track.merge(track.events)
}

play_track.recalc_times

#output.puts [0xF0,0x7F,0x7F,0x04,0x01,0x00,0x10,0xF7]

if true
play_track.each { | event |
  time=seq.pulses_to_seconds(event.delta_time)

  if MIDI::NoteEvent === event or
    MIDI::Controller === event or
    MIDI::ProgramChange === event or
    MIDI::SystemCommon === event or   
    MIDI::ChannelPressure === event or 
    MIDI::PitchBend === event or
    MIDI::SystemExclusive === event
    
  puts "#{event.delta_time} (#{time}) #{event.class}: #{event}/#{event.data_as_bytes}"
  sleep(time)
  output.puts event.data_as_bytes
else
  puts "IGNORED #{event.delta_time} (#{time}) #{event.class}: #{event}/#{event.data_as_bytes}"
  sleep(time)

end
}
end

rescue SystemExit, Interrupt
  puts "exit"
  16.times do |i|
    output.puts [0xB0+i,0x7B,0x00]
  end
end