Maisha is a London-based group, usually six to eight members strong, led by drummer Jake Long, who also does most of the writing. The compositions are consciously retro spiritual jazz in a modal…uh, mode, with long vamping melodies and grooves with an endless feel. Nubya Garcia doubles on sax and flute, but guitarist Shirley Tetteh is quite often the star, particularly on the nearly 12-minute opener, “Osiris.”