Hm. Choral concerts are thin on the ground this weekend, let me tell you. I can only offer you a couple of options on Sunday. (Friday and Saturday I suggest you explore other musical genres.)
On Sunday at 2:30 pm, you could attend one of the Cantata Singers Chamber Series concerts, titled "Vocal Chamber Music of Ralph Vaughan Williams and Friends." It will be at the Edward M. Pickman concert hall at the Longy School of Music in Cambridge.
Or, you could go to the Paretsky Center at Simmons College in Boston, and hear "Jaguza! Celebrate the Children of Uganda" where the Ugandan Martyrs Choir will perform with other native African singers to benefit the Malaka Fund, a non-profit based in Jamaica Plain.
That's all I got!
Did I miss anything? Leave it in the comments!