The boys have said they won't be waiting for Chase's birthday -- though it'll only be a few days before that event. The bad news is... I don't think they're selling tickets for that particular event so you're going to have to work hard to get ringside.
Actually, all we know is that Zeke's brother turned on Brandon. We don't know what sort of relationship Zeke has with his brother. It could be that Zeke hates his brother and will become friends with Brandon just to spite his brother (leaving aside the other music-related reasons for staying on Brandon's good side). Also, while Brandon knows enough about Zeke to know the name of the band he plays for (played for? Maybe he's no longer in that band. Band line-ups change, after all), it isn't stated how well Brandon and Zeke's brother know each other. Do they know each other by sight?
CJ -- yes, the coincidence is a stretch, but it's not one that disrupts the story. These things do happen from time to time. It's the total sum of the number of coincidences that stretches credibility to the limit and I don't think you're there yet. I'm assuming, like you have, that the music industry at that level is sufficiently small that it's not unusual for people to know each other.
If The Shadows are a good enough band to play at an Instinct concert, then it isn't unusual for Brandon to know about them, especially if one of the members is from his home town. Brandon knowing Zeke is more likely than Zeke knowing Brandon as a consequence, unless Zeke knows Brandon through his brother. Equally, musicians tend to congregate and so Brandon getting to know Zeke's brother (who I'm guessing also has a musical interest) isn't odd. This sort of thing often runs in families so it's not as big a stretch as it may first seem.
I enjoyed the chapter. The way they got out of the situation was Charity was good -- the same way they addressed the problem of Lump. I have to wonder, though, exactly how many blackmail check tapes/recordings Helen has.... They've made two new ones in only a couple of weeks.