I first read Songmaster in a Futura edition with 23 pages missing out of the middle. Intensely annoying, especially because I thought the book was so good, and because those pages were crucial. It probably helped to highlight the book's impact.
I recently included Orson Scott Card's Songmaster in a list of my top five SFF books. When someone asked why, I realized I hadn't read the book in so long that I couldn't answer in any detail. So, I reread it, and I'm happy to say my view hasn't changed
Songmaster brings together the separate concepts of Ender's Game (youth with talent and control, an impassive master), Capitol (needful destruction, tyrants with depth), and Unaccompanied Sonata (purity in music). Each of those works was first class, and Songmaster proves to be an equally worthy synthesis.
It's hard to point to specific moments in the book that demonstrate its quality. The fact is that, throughout, Card achieves an almost perfect balance of prose and feeling. All the notes are right, all the emotions credible, all of it very human. What takes the story beyond the ranks of merely 'excellent' is Card's ability to follow through. Many writers can bring a story and reader to an emotional crescendo, a satisfying ending. Very few writers are then able to pick up the pieces and keep going. Card achieves this deftly and surely, and with perfect balance.
There are a couple of missteps, of course, and one key plot element that's weakly handled. But overall, this is one of the finest SFF works of the last century. If it's hard to point out exactly why, it's because Card achieves the impact not with gimmicks or clever ideas, but with honest-to-goodness polished, effective prose. It doesn't have the flash of Vance, or the poetry of Zelazny, but it has more human characters than the one, and more emotional depth than the other. Card may not always be good, but this book is among his best.
Note: When I first read Songmaster, I knew very little about Card. I took the actions and desires of individual characters as the actions and desires of individuals. On this re-read, I still know very little about Card, but it was impossible not to consider his well-publicized and disagreeable views about homosexuality. It's certainly possible to read this book and come away uncomfortable with the way in which homosexuals are treated. That may reflect Card's worldview; I hope not. Nonetheless, even with this knowledge in the back of my mind, in my re-read, I still took the characters as individuals, and not intended to represent one or another group. Read in this way, the book is excellent. If you go looking for a fight, I think you can find one here, but I don't think you have to.