dedicated onboard triggers and lack of an integrated sequencer. Clonewheel organ modules are usually tabletop-style devices that enable keyboardists to recreate the sound of a tonewheel-based Hammond organ using any MIDI keyboard or MIDI-equipped stage piano. Organ modules may have drawbars and controls for a simulated Leslie speaker (a rotating horn and low-end baffle) effect. Some sound modules focus on piano sounds, typically providing grand piano, electric piano, and a few other keyboard sounds, such as clavinet. Wind controller modules are specialized synth modules that are designed to work with wind controllers. They typically support legato wind-style playing and can respond to the unique controller inputs, which sense breath, biting on the mouthpiece, and pressing keys. Wind controller players may use a specialized wind controller module such as the Yamaha VL70-m module or its predecessors, the VL-1 or VL-7. As well, wind controller players may use general-purpose rack synthesizers such as the Yamaha Motif XS Rack, Roland Fantom X, or the Roland Integra-7 rackmount MIDI sound module; however, these general-purpose synthesizer modules require extra wind sounds or patches to work well with wind controllers. An accordion module, which is designed for use with a MIDI-equipped digital accordion, focuses on providing synthesized or sampled accordion sounds (and sounds for related bellows-pumped instruments, such as bandoneon and concertina). Like other specialized sound modules, accordion modules also have other sounds (piano, string orchestra, flute, etc). More so than for other sound modules, accordion modules are likely to also have music sequencer, drum machine, and backing track features, to enable a performer to do a one man band show. Accordion modules are manufactured by firms such as Ketron and Soltron. Synth modules often have onboard effects units, such as reverb and chorus effect, or, for organ modules, vibrato and overdrive. Because most electronic instruments are designed in a modularized way, manufacturers often release a sound module version of their fully integrated instruments. For example, the 1980s-era DX-7 synthesizer/keyboard was also sold as a standalone sound module, the TX-7. A sound module may have all the other features of the controller-equipped version, but it often has a smaller display or limited programming controls. In this case, instrument and other sounds can be loaded through MIDI or external media. In some cases, sound modules have expanded capacity for sounds in comparison to the controller-equipped version. User interface The front of a rackmount sound module, or the