use samples for some sounds. Like the 808, the 909 was a commercial failure, but had a lasting influence on popular music after cheap units circulated on the used market; alongside the Roland TB-303 bass synthesizer, it influenced the development of electronic genres such as techno, house and acid. Later machines By 2000, standalone drum machines had become less common, partly supplanted by general-purpose hardware samplers controlled by sequencers (built-in or external), software-based sequencing and sampling and the use of loops, and music workstations with integrated sequencing and drum sounds. TR-808 and other digitized drum machine sounds can be found in archives on the Internet. However, traditional drum machines are still being made by companies such as Roland Corporation (under the name Boss), Zoom, Korg and Alesis, whose SR-16 drum machine has remained popular since it was introduced in 1991. There are percussion-specific sound modules that can be triggered by pickups, trigger pads, or through MIDI. These are called drum modules; the Alesis D4 and Roland TD-8 are popular examples. Unless such a sound module also features a sequencer, it is, strictly speaking, not a drum machine. In the 2010s a revival of interest in analogue synthesis resulted in a new wave of analogue drum machines, ranging from the budget-priced Korg Volca Beats and Akai Rhythm Wolf to the mid-priced Arturia DrumBrute, and the high-end MFB Tanzbär and Dave Smith Instruments Tempest. Roland's TR-08 and TR-09 Rhythm Composers were digital recreations of the original TR-808 and 909, while Behringer released an analogue clone of the 808 as the Behringer RD-8 Rhythm Designer. Korg released an analog drum machine, the Volca Beats, in 2013. Programming Programming of drum machines varies from product to product. On most products, it can be done in real time: the user creates drum patterns by pressing the trigger pads as though a drum kit were being played; or using step-sequencing: the pattern is built up over time by adding individual sounds at certain points by placing them, as with the TR-808 and TR-909, along a 16-step bar. For example, a generic 4-on-the-floor dance pattern could be made by placing a closed high hat on the 3rd, 7th, 11th, and 15th steps, then a kick drum on the 1st, 5th, 9th, and 13th steps, and a clap or snare on the 5th and 13th. This pattern could be varied in a multitude of ways to obtain fills,