Originated from Balboa Island, California where the dance floors were reputedly so overcrowded a 'closed' dance-style with lots of footwork (although the feet hardly leave the floor) the upper body remains still and the dance doesn't travel much around the room similar in style to shag but without such exuberant foot-work
Balboa works best for mid to fast tempo music, in contrast to Lindy Hop, Balboa is danced mostly in a closed position, though there break away moves. In terms of visual spectacle, Balboa is more of an intimate style - relying on subtle communication between partners.
Both LindyHop and Balboa developed over similar periods of the Swing era. Whereas Lindy seemed to developed from Charleston type patterns, Balboa is thought to have its roots in the Rhumba. Historically, Balboa was considered to be a more sophisticated, mature dance style than Lindy Hop. Today, LindyHoppers and Balboa dancers interchange the styles, most Balboa dancers came to the style via Lindy and incorporate Baloia into their Lindy; this is often referred to as Bal-Swing.
This is what wikipedia says about Balboa
Some clips of Balboa
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