In this one an additional low B string and a high C string is added to the usual 4 strings on basses to extend the scale possible to reach. But this guitar is mostly useful for improvisative players. Jazz, latin and funky are the most common genres using this instrument. For most dance songs you don't need that many strings that's why it is irrevelant in Congolese music. Especially because encircling such a wide guitar neck with your palm, so that your thumb would reach the low string, is extremely chellenging, that is an essential technique in Congolese bass anyway. People who use this guitar like to behave like soloists in the bass section or just use this to look cool.
