Night Forms, a public service of the arts platform and catalyzer Browntourage, is one of the several regularly occurring dance parties at the Rock Steady (1741 San Pablo Ave., Oakland). Keen to highlight varied narratives and backgrounds with its booking, Night Forms resident and guest DJs in turn foreground diverse, globetrotting selections in their sets. Thursday features Soisy — whose posted online mixes collide Cam’ron and Floetry, UK grime and early Aughts R&B — joins SelamX, an artist of Ethiopian descent who recently produced an enveloping mix to accompany the Afrofuturistic film series in New York. Night Forms, which is completely free, shouldn’t be a particularly radical dance party. In light of the homogeneity at regularly occurring events at most prominent local clubs, however, it is.