Swiss singer, perhaps

• Cowboy crooner, at times
• Singer heard in the Cliff Hangers game on "The Price Is Right"
• Old-time country singer, sometimes
• Jimmie Rodgers or Tex Owens, musically
• Alpine caller
• Alpine show-off
• One making frequent pitching changes?
• Matterhorn vocalist
• Alpine vocalist

Wiktionary Word definitions in Wiktionary
n. One who sings so that their voice fluctuates rapidly between their normal chest voice and a falsetto, one who yodels.