Walter Sickert & the Army of Broken Toys perform at Kelly Davidson’s “Rock Parents” exhibition at Once, Somerville, May 6, 2018. (Greg Cook)Walter Sickert & the Army of Broken Toys perform at Kelly Davidson’s “Rock Parents” exhibition at Once, Somerville, May 6, 2018. (Greg Cook)Walter Sickert & the Army of Broken Toys perform at Kelly Davidson’s “Rock Parents” exhibition at Once, Somerville, May 6, 2018. (Greg Cook)Walter Sickert & the Army of Broken Toys perform at Kelly Davidson’s “Rock Parents” exhibition at Once, Somerville, May 6, 2018. (Greg Cook)Walter Sickert & the Army of Broken Toys perform at Kelly Davidson’s “Rock Parents” exhibition at Once, Somerville, May 6, 2018. (Greg Cook)Walter Sickert & the Army of Broken Toys perform at Kelly Davidson’s “Rock Parents” exhibition at Once, Somerville, May 6, 2018. (Greg Cook)