My dad was a semi-professional singer ( the Liverpool UK area) in his younger days. His three big music heroes were Al Jolson, Bing Crosby and Jimmie Rodgers; indeed, his rendition of those performers classic songs amounted to impersonations. I loved him singing the Jimmie Rodgers stuff, complete with great yodelling. My favourites were "Hobo Bill's last Ride" and "Me and My old guitar".