For Good- WICKED. It's a duet, but I've seen it done as a solo (in cabaret shows). Every person I know who has heard it on the cast recording has cried listening to it.
The Story Goes On - BABY
There's a Fine Fine Line - Avenue Q
Lament - EVITA Again a duet, but can easily be done solo.
Too Much For One Heart - this song was cut from MISS SAIGON. But, Lea Salonga has a cd titled The Broadway Concert, on which she sings it the only time it has ever been sung in public. They replaced it in the show with "I'd Give My Life For You." Anyway, GORGEOUS song and I thank Lea for recording it.
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