From Wikipedia: Lawrence Welk was an American musician, accordionist, bandleader, and television impresario, hosting The Lawrence Welk Show from 1955 to 1982. His style came to be known ... as "champagne music."
The show holds the record for the longest running televised American music variety show, and ran nationally for 27-1/2 years. I remember watching it with my grandparents on, I think, Saturday nights. Most of the music was big band music, and Welk's catchphrase - wunnerful wunnerful - remains in the lexicon of those of us who were forced to watch the show as children.
The back of the postcard says: "Palm Springs, California. Hollywood's favorite winter playground. The winter resort home of Lawrence Welk". This postcard, probably from the 1960s, is typical of many that were sold at the time, showing the "winter resort homes" of a variety of Hollywood stars. If you've ever been to Palm Springs or Palm Desert, you've probably driven on Bob Hope Drive, Frank Sinatra Drive (actually in Rancho Mirage), Gerald Ford Drive, and even Kirk Douglas Way, which was named in 2004.
BTW, if you're interested in movie stars, particularly old school movie stars, you might check out Euopean Film Star Postcards. Every day, a different star is featured and the pictures and detailed background are really amazing.