Sequencers and digital audio workstations

Step Sequencing

• In step sequencing, the notes are entered into a sequencer’s memory one at a time onto a grid or series of buttons

• Step sequencers were built into a number of popular analogue synths during the 1970s, regular musical loops became a feature of the synth pop style.

• Sequencing is now ubiquitous across pop music, achieved in DAWs and audible in music throughout the charts.

Analogue sequencers

• Early sequencers sent CV/gD signals to trigger notes on a synthesiser.

• In order to do this, a voltage was sent from the sequencer to control the opening and closing of gates to play notes on a synthesiser module

• Ultravox are a famous example of a band who modified their equipment in the late 1970s and early 1980s, controlling analogue synthesisers from their drum machines

Digital Sequencing

• The later 1970s brought with them a number of digitally controlled analogue sequencers, which also used voltage control but with computer memory.

• Sequencer also formed part of synthesiser and samplers

• During the late 1970s and early 80s, step sequencers were included as part of the samplers produced by Syncalvier and Fairlight

MIDI

• MIDI was introduced in 1983 and became the common language used by electronic musical instruments to communicate with each other

• It also provided a link to a computer, the Ataria ST (1985) was built with MIDI ports.

• It was successful with amateur musicians and professional studios because it was easier to programme a sequence on the computer and send it through the MIDI ports to control a synth, sampler or drum machine, much like a MIDI track in Logic today.

MIDI Messages and Velocity

• A MIDI messages consists of a status byte and one or two data bytes. A status byte tells us the type of MIDI messages and the data bytes provide more info about the parameters associated with it

MIDI Controller Changes (CC)

Pitch Bend

• Can be used to continuously bend the pitch of a note up and/or down by a predetermined amount

• It can be programmed in using an expression editor or event list, or could be recorded using a wheel on a MIDI keyboard or control surface

• Synthesiser and electronic instruments normally allow you to alter the pitch bend range in semitones

• Pitch bend is not a controller, but another type of MIDI message. The status byte specifies that the messages for pitch bend, and what channel apply it to

• Two data bytes are used to communicate the amount of pitch bend, relative to the instrument’s pitch bend range.

• For velocity, each data byte can contain 7 bits of useful information about this

• There are 16,384 (128×128) possible values for pitch bend, with a value of 0 meaning maximum downward bend, 8,192 meaning no bend and 16,383 meaning maximum upward bend.

• Logic’s list editor displays this as a minimum of -8192, 0 as centre and +8191 as maximum and as -63 to +64 in piano roll.

OSC

• Open Sound Control (OSC) is a language or protocol that enables you to network synthesisers, computers, and other multimedia devices. It is a modern standard that is sometimes used as an alternative to MIDI

• OSC messages are transported across the internet and local networks with messages sent in a similar form to internet addresses. It is possible to send ‘bundles’ of messages whose effects must occur simultaneously

• OSC is sometimes used in experimental musical controllers to go beyond the constraints of MIDI

Drum Machines

• Drum machines use sequencing technology to create rhythmic patterns.

• Early drum machines relied on preset patterns

• In the late 1970s, the first programmable drum machines were introduced

Drum Machines - Historically important Drum machines

• Rhythmicon (1931) (first electronic drum machine)

• Roland CR-78 (1978) Blondie - Heart of Glass

• Linn LM-1 (1979) Prince - ‘When Doves Cry’

• Roland TR-808 (1980) Marvin Gaye - Sexual Healing

• Roland TR-909 (1984) Daft Punk - Revolution909

• Akai MPC60 (1988) Kris Kross - Jump