Slap bass is a technique that can be used on a bass or double bass guitar. It began in the 1920's and gained popularity in the 1940's. It is a technique that is used in many musical genres today. On the bass, it is found in disco, jazz, Latin, pop, soul, and funk music. On the double bass, the sound can be heard in country and rockabilly music. The distinct sound has been used to create original scores for movies, and can be heard on television in commercials and program theme songs. It can be mastered on both acoustic and electric bass guitars. It is considered a percussive technique that seems easy, but is actually complicated to learn.
Basically slap bass is played with the thumb and either the middle or the index finger. The thumb produces the slap, and the finger makes the pop, or pluck, sound by going underneath the string and pulling it away from the fret board. Other components of learning how to play slap bass include keeping the hand perpendicular to the strings, and the thumb has to be at a particular angle to the string that is being slapped. The thumb has to come down in a specific position and hit the bottom of the string slowly.
The other hand is used to mute the other strings while slapping and popping on one or two strings. When it comes down to getting a pattern and rhythm, it is really all in the wrist. At least one amazing slap bass lesson is needed, even for accomplished bass players.
Mastering the slap bass takes a lot of practice. Beginners need to keep in mind that arms will ache, fingers will shred and bleed, thumbs will blister until calluses can form. The wrist may be sore as well until players get used to the positions. The music is written with "S" and "P" across the top to denote when to slap and when to pop, and strings A, D, G, and E along the sides. There are many variations to the music style, and the speed contributes to the sound differences among genres. There are several videos online that demonstrate the technique, and courses are available to teach it to interested players. Learning this technique can make players more valuable to local bands, allow them to stand out from the competition at auditions, or make you the star of the high school band.