In contrast to the upright bass (also called "double bass"), the electric bass guitar is played horizontally across the body, like an electric guitar. When the strings are plucked with the fingers (pizzicato), the index and middle fingers (and sometimes the thumb, ring, and little fingers as well) are used. James Jamerson, an influential bassist from the Motown era, played intricate bass lines using only his index finger, which he called "The Hook." There are also variations in how a bassist chooses to rest the right-hand thumb (or left thumb in the case of left-handed players). A player may rest his or her thumb on the top edge of one of the pickups or on the side of the fretboard, which is especially common among bassists who have an upright bass influence. Some bassists anchor their thumbs on the lowest string and move it off the lowest string when they need to play on the low string. Alternatively, the thumb can be rested loosely on the strings to mute the unused strings.
Optical pickups are another type of non-magnetic pickup. They use an infrared LED to optically track the movement of the string, similar to the mechanism of modern computer mice, which allows them to reproduce low-frequency tones at high volumes without the "hum" or excessive resonance associated with conventional magnetic pickups. Since optical pickups do not pick up high frequencies or percussive sounds well, they are commonly paired with piezoelectric pickups to fill in the missing frequencies. LightWave Systems builds basses with optical pickups.
Maybe you've already got a specific brand in mind and want to see all the digital pianos they offer. All you have to do is click on the brand on the left hand side of the screen and within a few moments you'll have access to everything that's available. For that matter, you can always play is safe and stick to the top-rated items…and there are plenty of those in this selection.