Switch up your outdoor concert scene with the Orchestra of St. Luke’s performance on the Williamsburg Waterfront. The ensemble, now in its 37th year, has performed throughout the five boroughs in permutations ranging from full orchestra engagements at Carnegie Hall to intimate chamber music concerts at the Brooklyn Museum. This Tuesday, the orchestra will be performing “Just Add Water,” a program featuring classics from Rodgers & Hammerstein, Aaron Copland, and George Gershwin. The free concert doesn’t require tickets; just get there when the doors open at 6pm to guarantee a good seat.