When I was still playing the nite-club and bar circuit, the maximum time I permitted between songs was a few seconds at most. Often, when the intro to a song was playing, I would acknowledge some of the customers who were regulars, and if rememberd one of their favorite tunes, I would dedicate that somg to them during that time. That usuallly put them on the dance-floor of the nite club, and others would frequently join them.
When I play for a dance crowd, especialy when the dance-floor is packed, the time between songs is one to two seconds at most. Anything beyond five seconds and they're headed back to their seats. I sincerely believe this is where preplanning every job really pays off, especially if you utilize every tool at your disposal and have the ability to deviate from the plan to accommodate the nature of the audience.
Gary
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PSR-S950, TC Helicon Harmony-M, Digitech VR, Samson Q7, Sennheiser E855, Custom Console, and lots of other silly stuff!
K+E=W (Knowledge Plus Experience = Wisdom.)