I know the 1st song because it's on one of my grandpa's 78 rpm records. And I love this rendition of "In The Summertime"! Just to give you some info. on The Country Trio, here's what it says on The Muppet Wiki site:
"The Country Trio was a hillbilly band consisting of Muppet versions of Jim Henson, Frank Oz, and Jerry Nelson. Jim played banjo, Frank played bass, and Jerry played guitar."
So the muppets in the trio actually look like their puppeteers! So cool! I do love how Jim Henson sang the line "Cause you don't want my love" with his face all smooshed up! LOL