The Roland TR-505 Rhythm Composer is a drum machine and MIDI sequencer released by Roland Corporation in 1986. It hails from the same family of drum machines as the Roland TR-909, TR-808, TR-707, TR-626 and TR-606. The drum kit includes basic rock drum sounds similar to those of the TR-707, plus a complement of Latin-style drum sounds similar to those of the TR-727 (the Latin version of the TR-707) Voice synthesis Samples in the TR-505 are stored as 8-bit unsigned PCM waveforms at a sample rate of 25 kHz. A non-linear DAC is used to simulate a 12-bit resolution. The TR-505 offers some major improvements over the TR-707, including 16 digitally recorded PCM drum sounds (four more than the TR-707) and five Latin percussion voices from the TR-727, reducing the need to buy a separate unit or PCM card. Summary of Drum Voices: Although there are 16 drum samples, the TR-505 only has an 8 voice polyphony, restricting some sounds from playing simultaneously: Low Conga or Hi Conga; Timbale, Low Tom, Mid Tom, or Hi Tom; Low Cowbell or Hi Cowbell; Hand Clap or Rim Shot; Crash Cymbal or Ride Cymbal; Closed Hi-Hat or Open Hi-Hat. The TR-505 offers very limited voice editing in the form of Volume, Velocity, MIDI Channel, and MIDI Note of each voice as a global parameter. Sequencer The TR-505 contains 48 factory sequencer patterns, organized into 3 pattern groups (A, B, and C). The drum machine can also store 48 user created sequencer patterns, organized into 3 pattern groups (D, E, and F). The TR-505 features five basic modes, including the following: Track Play - plays whole tracks (arrangements of patterns to form songs). Track Write - sequence patterns into tracks. Step Write - sequence patterns by stepping through each position in the pattern. Tap Write - sequence patterns by tapping drums sounds in real time. Real time - play patterns in real time by tapping the pads. An accent can be applied to any position in a pattern and will affect all instruments triggered at that position by increasing output volume. Users can copy, insert, or delete one or more steps in any given pattern, and copy, insert, or delete patterns anywhere in a track (song). Each individual pattern is a single measure long, The default time signature is 4/4 consisting of 16 steps and quarter note scale, resulting in each step representing a