A ballad also stood out in Chico Freeman’s curtain-raiser. The Chicago-raised saxophonist got to the bittersweet essence of “To Hear a Teardrop in the Rain” with unaccompanied high notes and a round, muscular warmth, rooted in the blues. Elsewhere, “Elvin” was inspired by the late drummer Elvin Jones, “Erica’s Reverie” was fugue-like and the closer an up-tempo romp. Sax and rhythm quartets have space to fill, and at this show, Freeman and pianist Luke Carlos O’Reilly delivered with unflagging invention and style. Freeman hasn’t played in London for more than a decade, and this imperious set was a welcome return.