Use in bluegrass

The string bass is the most commonly-used bass instrument in bluegrass music and is almost always plucked, though some modern bluegrass bassists have also used a bow. The bluegrass bassist is part of the rhythm section, and is responsible for keeping a steady beat, whether fast, slow, in 4/4 time, 2/4 or 3/4 time. The Englehardt and Kay brands of laminate basses have long been popular choices for bluegrass bassists. Most bluegrass bassists use the 3/4 size bass, but the full and 5/8 size basses are also used.

Early pre-bluegrass music was often accompanied by the cello, which was bowed as often as plucked. Some contemporary bluegrass bands favor the electric bass in an effort to avoid transporting a very large yet delicate instrument on road trips and tours, but it has a different musical quality than the plucked upright bass. The upright bass' slower attack and its percussive, woody tone gives a more "earthy" or "natural" sound than an electric bass, particularly when gut strings are used.

Common rhythms in bluegrass bass playing involve (with some exceptions) plucking on beats 1 and 3 in 4/4 time; beats 1 and 2 in 2/4 time, and on the downbeat in 3/4 time (waltz time). Bluegrass bass lines are usually simple, typically staying on the root and fifth of each chord throughout most of a song. There are two main exceptions to this "rule". Bluegrass bassists often do a diatonic "walkup" or "walkdown" in which they play every beat of a bar for one or two bars, typically when there is a chord change. In addition, if a bass player is given a solo, they may play a walking bass line with a note on every beat or play a pentatonic scale-influenced bassline.

An early bluegrass bassist to rise to prominence was Howard Watts (also known as Cedric Rainwater), who played with Bill Monroe's Blue Grass Boys beginning in 1944.^[10] One of the most famous classical bassists, Edgar Meyer, has frequently branched out into newgrass, Old Time, Jazz, and other genres.

Slap-style bass

Slap-style bass is sometimes used in bluegrass bass playing. When bluegrass bass players snap the string by pulling it until it hits the fingerboard or hit the strings against the fingerboard, it adds the high-pitched percussive "clack" or "slap" sound to the low-pitched bass notes, sounding much like the clacks of a tap dancer. Slapping is a subject of minor controversy in the bluegrass scene. Even slapping experts such as Mike Bub say, "...don't slap on every gig" or in songs where it is "not appropriate." As well, bluegrass bassists who play slap-style on live shows often slap less on records. Bub and his mentor Jerry McCoury rarely do slap bass on recordings. While bassists such as Jack Cook slap bass "...on the occasional faster Clinch Mountain boys song", bassists such as "...Gene Libbea, Missy Raines, Jenny Keel, or Barry Bales [rarely] slap bass."^[11]

Bluegrass bassist Mark Schatz, who teaches slap bass in his Intermediate Bluegrass Bass DVD acknowledges that slap bass "...has not been stylistically very predominant in the music I have recorded." He notes that "Even in traditional bluegrass slap bass only appears sporadically and most of what I've done has been on the more contemporary side of that (Tony Rice, Tim O'Brien)." Schatz states that he would be "... more likely to use it [slap] in a live situation that on a recording - for a solo or to punctuate a particular place in a song or tune where I wouldn't be obliterating someone's solo.".^[12] Another bluegrass method, Learn to Play Bluegrass Bass, by Earl Gately, also teaches bluegrass slap bass technique.