Deliberate mistake: When Evan/August first meets Arthur at the park, after playing, you see Arthur leaving his spot without taking the cable and (presumably) the amp as well.
Wizard: Can't you see it? Wizard productions presents the number one heat wave: august rush.
August Rush: Yeah! Me! That's me.
Question: What was the significance of showing us Lyla dropping her necklace outside the hotel? Louis didn't pick it up did he?