Having just seen a production of INTO THW WOODS (I have seen 12 over the years) it never fails to amaze me how rich, how dense and how bloody enjoyable the show is.
True, much of the music is not simple straightforward melody. When writing wordy songs, Sondheim wants us to focus on the words, while more simple lyrics are accompanied by lush melodies. Anyone who says Sondheim can't write a melody need only listen to "Children Will Listen" or "No One is alone."
The score weaves together many different music and lyric ideas into a wonderful tapestry. James Lapine's book is clever beyond words, despite a second act that dwells on reaction rather than action for much of the time.
The diction on the OCR is impeccable - esp Bernadette Peters' rapid fire "rap" about zapping vegetables. (Didn't your friend loan you the booklet with the synopsis and lyrics?) And yes, why no use rap in a musical if it is appropriate (and here it is VERY appropriate, giving the witch feistiness. Rock music is all about anger, after all.)
I would suggest giving it a few more listens (following with the libretto) or better yet see the VHS or DVD of the original Broadway production.
I guess its back to my wicked cd for now. This is the most troubling part of your post. WICKED does not have anywhere near the level of sophistication in music, lyrics or text that INTO THE WOODS has. The more you listen to WOODS the more you will discover about the score. (There was a list here recently of about 2 dozen musical and verbal motifs.) If WICKED and all the other current Broadway shows had 1/4 of the thought and effort put into their creation as has WOODS, Broadway would be much more rewarding
Cast albums are NOT "soundtracks."
Live theatre does not use a "soundtrack." If it did, it wouldn't be live theatre!
I host a weekly one-hour radio program featuring cast album selections as well as songs by cabaret, jazz and theatre artists. The program, FRONT ROW CENTRE is heard Sundays 9 to 10 am and also Saturdays from 8 to 9 am (eastern times) on www.proudfm.com