I have been a huge fan of the Muppets since my own childhood, dutifully collecting their DVD's, merchandise, and hungrily reading any Henson biography I came across. That being said, I was very pleased with "The Green Album"; I felt that all of the songs were true to the originals, yet still modern and fun.
I played this o a road trip with my kids - ages 2 and 5 - this weekend, and they loved it! My daughter, who is older, had seen all of the Muppet movies, so she was familiar with some of the tunes ["Mahna Mahna" is actually my ring tone!]. The lyrics always my her smile, while the peppiness of the melody kept my son clapping in his carseat.
"Moving Right Along" was probably our favorite track. I love the wordplay - I smile just as much as my daughter listening to this song! But every track gives you something to think about. One of the things I admire most about Henson is his positive view of the world, and the sense of innocence that all of his characters - even the villains - held. I find his work inspirational in this sense, that there is no cynicism, no greed, no cruel irony to the characters he wrote. That stayed true in "The Green Album".
I'd recommend this to any family - mom and dad will enjoy it as much as the kids! And at the end, everyone has something positive to think about.