I had a number of issues with this book. First, Merlin is a dick. I understand that he's supposed to "grow" so he starts out as a dick and then learns to be better, but when he changes so much from the character in the previous book, with little to no explanation, it doesn't work. I mean, having a character who is afraid of his powers and doesn't think he can ever become a wizard walk around acting like he's owed admiration for being given a magical harp - it makes no sense without some explanation.
Second, there's no real consequences for any of his actions. He abandons his task to go find his mom? Sure, it was said that abandoning his task would lead to the destruction of the island but really, there's no issue. He is supposed to find all seven songs, and if he tries to continue his quest without finding all seven, he'll die? Nah, don't worry, someone's always around to save your ass. Your sister dies? Nah, it's cool bro, a god will save her. And of course his mom doesn't die. I mean how is this little shit supposed to learn to listen and follow directions if none of his mistakes actually have any negative consequences? I can understand bailing out a character in a magical world maybe once or twice, but eventually you're telling the reader that none of the actual issues matter because somehow everything will get magically better. That isn't interesting to read.
Third, I had a problem with the whole writing style and just choices for how the plot went along. The pace was strange because the characters kept whining about running out of time but it was like everything happened so quickly. I never felt like there was any rush, especially when other characters popped in and used their magic to help the group go along their way. This relates back to my point about no consequences because once or twice I could accept that they received help, but when every other time it's "oh no, how will we get there in time, it's so far" and then POOF, magical friend here to save the day, it just becomes boring.
Quick side note: what on earth was the point of Nimue stealing Merlin's staff? The writer gets to devote one chapter to Merlin's magical friend helping him get it back in like minutes and then back to the main plot? Why? It's so useless! If you're going to have his magical staff taken from him, make him work for it or something. Turn it into an actual lesson for him to learn. Give us a reason. UGH.
Also, many of the ways Merlin uncovered the "souls" of the songs was ridiculous (who thinks, when their knife breaks, instead of asking for a new one from the many workers around you, "oh I'll just grab this old sword on the wall"?). And putting the "soul" of the song in italics was really off-putting to me. It was unnecessary. I can grasp what the moral is without the help, thanks.
If I didn't have a reason to finish these books, I wouldn't. I would've quit in the first fifty pages and gone to read a book that I actually enjoyed.