THEME: MEMO found in phrases [pity this clever theme is part of a tradition of cleverness-shorn Monday offerings]
GOOD ONES: Office communication {and theme} INTERNALMEMO [clever in that MEMO is internal to the phrases]
BTW: Scat legend Fitzgerald ELLA [as SCAT can be scatological, I should think a better clue can be found for the great singer]
Like a slingshot handle YSHAPED [as I see it, the handle is I-shaped; the slingshot itself is Y-shaped]
There were three baseball references today but six weeks before opening day.
RATING:

Three grins = Loved it; Two grins = Enjoyed it; One grin = A bit bland for my taste; One teardrop = Not much fun