이규항 / Lee Gyu-Hang (Yig Yu-Hang)
You can find tracks here:
가요(歌謠) 박물관 Music Museum 220 Best
CD6-2 네잎 크로바 / Four Leaf Clover (1968)
This track sounds like a cowboy song with deep warm voice. First of all there's this horse walk rhythm. But we also have some arrangements of soft lush strings and electric guitar rhythms.
PS. On YouTube you can only find more recent karaoke versions of this song.