Passing lambda as a constructor parameter in Sonic Pi

test_melody.rb

test = lambda { |ctx|
  puts "#{ctx.class}"
  ctx.notes.each do |note|
    play note, amp: 0.5
    sleep 0.25
  end
}

class TestMelody
  attr_reader :notes
  
  def initialize(block) # accepts a code block
    @notes = [:C5,:D5,:E5,:F5,:G5,:A5,:B5,:C6]
    @block = block
  end
  
  def play
    @block.call(self) # calls code block with reference to itself
  end
end

live_loop :testing do
  mel = TestMelody.new(test)
  mel.play
end