Echo, A Novel by Pam Munoz Ryan (sorry I don't know how to add a tilde to her middle name,) is one of the best books I've ever read, and I've read thousands.
It's a long book - nearly 600 pages - but I finished it in one day because it was too good to put down.
It's actually four books that are all part of one story.
Starting in the 1800s a boy named Otto encounters three strange women in the woods and gets a magical harmonica. That instrument is an important factor in the lives of other kids: Mike in 1935, Ivy in 1942, and Friedrich in 1951. The story and harmonica begin in Germany, then move to Pennsylvania, California, and New York.
Each story has it's own plot, is well written, and they all tie together satisfactorily at the end. The book is part fairy tale, part historical fiction, and all exciting stories with characters we care about.
Pam Ryan has got to be one of the best writers on this planet and I can't wait to read other books she's written.