Easy listening is a style of popular music and radio format that emerged in the mid-20th century, evolving out of swing and big band music, and related to Beautiful music and Light music. Easy listening music features simple, catchy melodies, soft, relaxing songs and occasionally rhythms suitable for couples dancing. The genre includes both instrumental forms (often played on light of tone instruments such as the Hammond Organ, violin or ukulele); and vocal forms featuring pop singers and some exotica artists. Easy listening is similar to what is called lounge music, but lounge is more jazz-oriented and dependent on musical improvisation than easy listening. Easy listening music is usually orchestrated by an arranger rather than improvised by a small ensemble.