How did this one get under the radar? Week after week, we get dimwitted comedies, and then a charmer like this comes along, and it gets a limited release. Why Stop Now is a bright screwball comedy about one fraught day in the life of a piano prodigy, his crackhead mother and her drug dealers. It s the first movie in memory that when the kid is performing onstage and the door at the back of the auditorium opens, he does NOT want a parent to appear. Why Stop Now opens with the crucial audition of Eli Smith (Jesse Eisenberg), who could win a scholarship to a famous music conservatory. He arrives late and explains to his teacher that he has had a very hard day. It began with his driving his mother Penny (Melissa Leo) to a drug rehabilitation clinic. She isn t enthusiastic about this; he nearly has to carry her in.