Analog Sequencer

In music creation, a type of sequencer that does not use digitized performance information like we are accustomed to in modern designs. Analog sequencers were common in the 1970’s and early 1980’s, until digital sequencers came along and with their vastly more comprehensive capabilities made analog sequencers obsolete. Most analog sequencers work by manually setting a series of note values in a sequence. This may be as simple as having a series of sliders (like a graphic equalizer) that each control a VCO (Voltage Controlled Oscillator). Each slider in a series is set so it causes the VCO to play a particular pitch or note. A clock source causes the “sequencer” to step through these sliders so each one is read individually one right after the other. The result is playing a sequence of notes based on the values of the sliders and the speed of the clock. Analog sequencers may have just a few steps available, or they may have many steps and some method to disable or mute some steps for rests and shorter sequences. Analog sequencing has made a bit of a comeback in recent years as part of the trend towards “retro” equipment. While not offering anywhere near the depth of versatility of a digital sequencer, they do have some advantages in that they are easy to program without having to perform the musical part and they are easy to interface with analog synthesizers.