I 1st-visited Harvard Sq. in '58 to buy both a hard-&paper-back copy of William Empson's THE 7 TYPES OF AMBIGUITY for my sr. yr. RC prep-school English teacher, Bro. Kyrin Powers, who'd suggested we read it.
I had my 1st English (Mackeson's London) stout there (at the Wursthaus) with Jeff Gutcheon, Maria Muldaur's pianist, during the Summer of '62 while I was at Harvard Summer School, taking Chaucer's minor poems, still being given by the legendary B.J. Whiting.
Joan & Maya & Alex & I lived in Cambridge (in Central Sq.,) from '64-72, & were, of course, often in Harvard Sq. during what I call The Years of Flame (=the High-'60s)
I was last in Harvard Sq. in '03; while Carolin & I reduced the contents of the Wellesley Sq. apt. to move to CA, I kept bringing all my extraneous poetry books to donate them to the Houghton Library's Woodbury Poetry Room because it was now too poor to buy more (its early-20th c. bequest had become pitifully inadequate by the early-21st c.) Things had changed, even inside Harvard, between 1958-2003.
Once charming Harvard Sq. is now dense with traffic & the MBTA subway goes all the way to Porter Sq. Do people still busk at night in the former COOP (now Barnes & Noble's) 's portico? Sure; I'm told they now even sit begging 24/7.