She also had another role of distinction: that of a sort of "mother spirit" for musicians. Her spacious Harlem apartment was a "salon" where, especially in the 1940s, many prominent jazz musicians hung out, especially, though not exclusively, those musicians whose style was on the cutting edge.

I was a friend of Mary Lou's and particularly remember when, in 1947, she had me show up at her place for an evening gathering. The turnout was small, but choice.Among the group that appeared there were three disparate geniuses who were, or became, member's of Down Beat's Hall of Fame: Dizzy Gillespie, the trumpeter and bebop icon; Jack Teagarden, the premier trombonist of the era; and Mary Lou herself.

To top it off, there were two of the most prominent boppers: pianist-arranger Tadd Dameron and pianist Hank Jones. It was a serious social gathering. No jamming. Just serious talk, mostly about music, with some attention to recordings played on Mary Lou's small phonograph, and occasional moments at the piano by one or more of the guests, to illustrate a point. As for the usually flamboyant Dizzy, he had no horn but smoked a pipe, looking as if he were an elder statesman. The hostess, for her part, was all dressed up, with a corsage pinned to her dress.

Finding Jack Teagarden in that group was surprising. Here, among the boppers, was the laid-back Texan trombonist and singer who was a celebrated touring partner of Louis Armstrong and a frequent member of old-time combos. But everyone loved the guy, for his personality and musicianship.