Well,
here's my favorite bassist, Michael Manring, playing his tune Monkey Businessman.
Lest anyone be confused, that's a four-string electric bass he's playing,
not an electric guitar. And it's a fairly special electric bass.
First, it's fretless, like a violin: he can stop any of the strings at
any pitch, not just those corresponding to white or black keys on a piano.
Second, it has a three-octave fingerboard. Most electric basses have a one-and-a-half-octave fingerboard, meaning that the lowest and highest notes you can play on any one string are an octave and a half apart. That's why the body is cut away so severely just below the neck: so that his left hand can reach the entire fingerboard.
Third, the reason the head looks so strange is because each of the four strings has a Hipshot detuner on it. That's a device that enables you to tune a single string to two distinct pitches, and then switch it between those pitches by flipping a lever. He uses this a couple of times to change the tuning of his bass in the middle of the song. This particular bass also has detuners in the bridge, although he doesn't use them for this song. (Look for "The Enormous Room:" in that one he's constantly retuning the bass.) That means each of his four strings can have any of four distinct pitches, for a total of 256 possible tunings.