Bassline

In solo music for piano and pipe organ, these instruments have an excellent lower register that can be used to play a deep bassline.

In swing jazz and jump blues, basslines are often created from a continuous sequence of quarter notes in a mostly scalar, stepwise or arpeggio-based part called a "walking bass line".

In Latin, salsa music, jazz fusion, reggae, electronica, and some types of rock and metal, basslines may be very rhythmically complex and syncopated.

In general, the more complex passages and rapid note sequences are given to the cellos, while the basses play a simpler bassline.

The timpani (or kettledrums) also play a role in orchestral basslines, albeit confined in 17th and early 18th century works to a few notes, often the tonic and the dominant below it.

[The bass part is] the foundation of harmony.In many genres of modern traditional music (ranging from folk rock to blues) and popular music (ranging from rock and pop to reggae to funk), the bassline is generally played by an electric bass player.

In rockabilly, psychobilly, traditional blues and bluegrass music, the bassline is played by a double bass player.

In most traditional and popular music styles, the bass player is expected to be able to improvise a bassline which they base in the chord progression of a song.

Rhythmic variations by the bass, such as the introduction of a syncopated figure can dramatically change the feel of a song, even for a simple groove.

Some songs lend themselves to another type of variation: the pedal point, in which the bassist holds or repeats a single note (often the tonic or the dominant) under the chord changes.

While walking bass lines are most commonly associated with jazz and blues, they are also used in rock, rockabilly, ska, R&B, gospel, Latin, country, and many other genres.

Bach's Nun komm, der Heiden Heiland, BWV 659, from the Great Eighteen Chorale Preludes):

Walking bass often moves in stepwise (scalar) motion to successive chord roots, such as often in country music:

In bebop jazz, the walking bass has a stabilising effect, offsetting and providing a foil to the complexity of the improvised melodic lines, for example in Sonny Rollins’ “Blue Seven”.

In some cases, a bass run may incorporate a display of virtuoso techniques such as rapid passages or high notes.

[8] In a rock song in which the bassline consists of low-pitched quarter notes played on the electric bass, a bass run may consist of a rapid sequence of sixteenth notes in a higher register, or of a melodic riff played in a higher register.

In some cases, the bassist will select a "brighter"-sounding pickup or increase the treble response of the instrument for a bass run, so that it will be easier to hear.

In a heavy metal song where the bassist was ordinarily playing low notes without overdrive to accompany, for a solo, they may turn on a fuzz bass pedal and use a wah pedal to create a more pronounced tone (an approach used by Cliff Burton), and then play an upper register riff or scale run.

In a psychobilly band, a bass solo will often consist of a virtuosic display of triple and quadruple slaps, creating a percussive, drum solo-like sound.