A brownstone stoop morphed into a sidewalk stadium for South Slope revelers, who rang in Year 2010 with a rip-roaring rock show — complete with a “ukulele drop” as the clock ticked towards midnight.

The sixth annual celebration jumpstarted New Year’s Eve festivities in front of Ukulele Drop, 321 23rd Street, where Brooklyn band Sonic Uke performed on their four-string guitars and struck the right chord with merrymakers, who rivalled their Times Square counterparts in dispensing good cheer.