Garrison Keillor’s variety show A Prairie Home Companion evokes different reactions in me depending upon the type of segment on when I tune in. The humorous skits make me hastily and forcefully turn the radio off, annoyed that public radio lives up to its reputation for corniness.  Keillor’s stories of life in the fictional Lake Wobegon may get me to stay, depending on my mood. But the music always hooks me. Whether it’s Keillor, with his lovably everyday voice, singing or a guest, the musical portion of the show is in touch with the rich country, folk, bluegrass and gospel heritage of America.

Robert Altman’s film version of A Prairie Home Companion drew much of its emotional force from the choice to focus on the musical side of the show, over the skits. Along with its stable of Hollywood actors, the film featured radio show “regulars”. Among them were Robin and Linda Williams, a husband-and-wife duo whose first appearance on the show was in 1975, the year after its debut. The Williams’ first album together was also released in 1975. After that they released another 17 albums and appeared on the show numerous times. Radio Songs, their 19th release, summarizes that side of their career by collecting together 19 performances that aired on A Prairie Home Companion, during nine shows recorded between 1995 and 2005.

Radio Songs is a time capsule as much as a music collection, then. It captures specific moments at particular places and times. The places include historic venues like The Fitzgerald Theater in St. Paul, Minnesota, the nearly 100-year-old theater where the radio show debuted, and the immortal Ryman Auditorium in Nashville, Tennessee. The musicians playing with the duo depended on who else was on the show that day. They’re joined by Mountain Heart, by Pete Seeger’s half-brother Mike Seeger, by the show’s house band Guy’s All-Star Shoe Band, by Keillor himself. And the music itself is a look towards the past, either in style or actual heritage. The songs reflect the history of American folk music. One song, “I’ll Twine Mid the Ringlets”, dates to 1860. Others are undated traditional songs, or numbers by legendary songwriters like A.P. Carter or Charlie Poole. And the songs written by the Williams themselves are in this same vein, with an understanding of not just the musical style but also the human concerns of the songs themselves.

There’s a deep sadness to so many of these “old time” songs, spurred on by loneliness, heartbreak or a sense of homelessness. A.P. Carter’s “By the Touch of Her Hand”, sung with shattering directness by Linda Williams, describes “days so dark” amid “lonesome pines”, as lovers are separated. “I’ll Twine Mid the Ringlets” tells a similar tale, with Williams again at the lead, singing “my visions of love have all faded away.” Late in the album, a “Home, Sweet Home Medley” of what Robin Williams describes as “old sentimental ballads”, including Jimmie Rodgers’ “Daddy and Home”, Left Frizzell’s “Mom and Dad’s Waltz” and the traditional “Precious Memories”, look nostalgically back to childhood through a lens of present-time sadness.

That looking backwards to “home” is often paired with a looking forward to a future sense of home. The hope that balances the sadness of these songs is so often a spiritual hope, a belief that the pain of life gives way to the joy of the afterlife. 1995’s Good News was a gospel album, and Robin & Linda Williams have often sung, and written gospel songs. Several of their original songs here reflect this spiritual longing for a place of comfort; what one song title refers to as “The Other Side of Town”. Their version of the sometimes schmaltzy 1939 song “We’ll Meet Again”, recorded for a show featuring songs of World War II, takes on a spiritual quality, both due to Linda Williams’ singing of it and the song coming after their acapella rendition of the gospel song “Feed My Sheep”. Their “So Long, See You Tomorrow” takes the same “see you soon” sentiment and makes it explicitly about the afterlife, with the protagonist confessing life’s regrets and dreaming of a “morning free from sorrow”.

This combination of current-day struggle with the hopeful promise of a peaceful future is integral to these old-time songs, and to the undercurrent of melancholy that runs through A Prairie Home Companion, even at its hokiest. There’s always that sense that you laugh, and sing, to express the tears you dare not cry. Robin and Linda Williams are not free from hokum themselves; the CD ends with their radio-skit personas Marvin and Mavis Smiley doing a jokey bluegrass run-through of music from classic, and, not coincidentally, tragic, operas. Yet the straightforward, reverent way that they tackle traditional folk music expresses an appreciation for this style of music and the circumstances driving it. Radio Songs displays an understanding of hard times equal to an understanding of the way people use music to get by and rise above, together.

• "So Long See You Tomorrow" MP3