Agreed. A few people are getting confused here. The concert key doesn’t change. It’s C minor. Like Greg, I’ve often seen this book whilst teaching. It was handy as you could have any sax or clarinet walk through the door and you could accompany them on the piano whilst they played the tune.Don't over think it. I find it easier to think in concert. Song is in Cm. So Am for alto Dm for tenor. That's it.
Simply tenor needs to play tone or 2 semi tones up. Alto needs to play minor3rd or 3semi tones down.
The best thing to do is get Band in a box.