When it came out in 1956, it was marketed as a "bass guitar" – tuned like a guitar, only a full octave lower. while it wasn't an instant hit, it did find its way to an impressive amount of country, rock and roll and surf records, and it's an instrument you can hear on movie/TV soundtracks and themes, from "Daktari" all the way up to Twin Peaks.
This modern day version is a pretty faithful replica of the original, updated with an adjustable truss rod and bridge, and comes with lighter strings in a B-Baritone tuning. This means your lowest string is a B – and what would normally be your A string is now the same pitch as a standard guitar's low E.
A heavier set of strings and a setup will still allow you to tune it as a six string bass – i.e. a guitar in the bass register.
The resurgence of Baritone guitars has shown that these instruments can't just do the familiar retro stylings they've become know for, but they're extremely adaptable to virtually any style of music, be it pop, funk or low tuned metal.