The word choirmaster is playable in Words With Friends™, no blanks required. Because it is longer than 7 letters, you would have to play off an existing word or do it in several moves.
Words With Friends™ Letter Score: 19
Highest Scoring Words With Friends™ Plays In The Letters
Seven Letter Word Alert: (96 words)
achiest, aitches, archers, armoire, armrest, artsier, atheism, atomics, atomise, carries, carrots, carters, cashier, chamois, charier, chariot, charmer, charter, chaster, chemist, chimera, chromes, cithers, coarser, coaster, coheirs, corsair, crasher, craters, creator, cristae, crosier, earshot, erotica, erotics, erratic, hamster, haricot, hastier, hermits, heroics, heroism, hoarier, hoarser, homiest, horsier, maestro, marcher, marches, marries, matcher, matches, metrics, mishear, moister, mortars, mortise, mothers, octamer, ostrich, raciest, reactor, rechart, recoats, rectors, reharms, rematch, reroast, retrims, rhetors, rhotics, richest, rioters, roaches, roamers, roaster, roister, scarier, scoriae, shorter, smarter, smartie, smother, somatic, stomach, tarries, thermic, thermos, torches, tracers, trasher, tremors, triarch, trimers, trocars, trochar