They began as a big band but have since grown bigger. The Jazz Jamaica All Stars, nowadays a 20-piece band, started out as an ambitious nine-piece, under the briefer band name Jazz Jamaica, a little over a decade ago. Both name and music have since been stretched further. The British-Jamaican act, which plays an ebullient mix of ska, reggae, mento and jazz, and features three generations of musicians amid its ranks, will return to Athens for one show this Saturday at the open-air Lycabettus Theater. The band’s more compact, original lineup performed here just prior to the act’s expansion, in 1999. Led by the group’s founder, Gary Crosby, the act’s bassist, the Jazz Jamaica All Stars draw on 50 years of influences stretching from the jazz and calypso of the UK’s first-generation Caribbean immigrants to today’s eclectic scene. In guiding the Jazz Jamaica All Stars over the years, Crosby has striven for what he describes as a «good balance between happiness and discipline,» or the right mix between musical prowess and dance-provoking pleasure, both for the musicians on stage and audiences below. Combining the fast, off-beat rhythm of ska – a faster form of reggae from which the latter developed – with intricate jazz melodies played by leading British jazz players, the music of the Jazz Jamaica All Stars combines pleasure with prowess. Crosby considers his group primarily as a dance act, but remains vigilant to the perils of having too much fun. «On stage, we like to dance and play. You’ve got to be careful because the music can get sloppy,» said Crosby. «When musicians improvise in jazz, they really stretch out and get dangerous. When you improvise in reggae and ska, you try to push the dance element further. In our band’s case, the soloist has the opportunity to intensify the rhythm of reggae,» he added. Having too much fun, at least physical, would probably be out of the question for some of the group’s more seasoned members, now in their 70s. The on-stage activity is usually left for for the act’s more youthful members The youngest are in their early 20s. The group’s age mix, Crosby says, has an impact on its touring schedules. «We’re a dance band and need to keep a little energy for ourselves. I’d say a two-week stretch in one go is our limit. Let’s not forget, there are young and old in this band. We also have pensioners on board. I think most of us don’t want to spend too much time in the back of a van. We’ve done that in the past,» Crosby said. Also on the bill will be the local saxophonist Dimitris Vassilakis, one of Greece’s leading jazz players, who will be accompanied by two respected New York-based musicians, Jeff «Tain» Watts on drums, and Essiet Okon Ossiet on bass, for a set of contemporary jazz.