In this sympathetic follow-up to Horace and Morris but Mostly Dolores, Howe and Walrod depict a girl mouse's frustrated singing attempts and leaven it with humor. "Horace and Morris but mostly Dolores loved to sing." When they make music, Horace hits "the high notes." Morris provides "the low notes." Dolores, whose voice-bubble "La la la" is inscribed in a wavery line, sings "notes no one had ever heard before." No one minds, least of all Dolores, until she suggests the three audition for Moustro Provolone, a choral director with an artistic curl in his mustache and a collection of metronomes and record players. Aspiring performers will share Dolores's painful shock at the call-back sheet: "Horace. Morris. Chloris. Gus." Where other authors might show a child finding consolation in a different talent, Howe takes the difficult route. Dolores adores singing and rebuffs a pal's patronizing remark that "the audience is important too." In a kindly resolution that calls to mind Kevin Henkes's deft handling of grade-school matters, Dolores pens an imploring note to the Moustro, who raves at her rhymes: "This would make a great song!... Of course you must be in the chorus to sing it." Dolores gets lessons, and Walrod's endearingly odd acrylics picture the tin-eared chanteuse trying her best among her pearly-toothed peers. Howe and Walrod never treat success as a given and, as in the previous book, they suggest persistence serves a mouse well. Ages 4-8. (Oct.)