Co-written and first recorded (as an instrumental) by The James Last Orchestra (1969).
Hit versions by Nick DeCaro (MOR #22 1969), Petula Clark (US #62/MOR #12 1969/AUS #22), Andy Williams (US #22/MOR #1/UK #19/AUS #22 1969).
From the wiki: “‘Happy Heart’ was written by James Last and Jackie Rae, and was first recorded as an instrumental by The James Last Orchestra in 1969. It was first covered by Nick DeCaro, a version which enjoyed modest success in the US on the Billboard Easy Listening chart. ‘Happy Heart’ would go on to be recorded by both Petula Clark and Andy Williams, and released as a single by each almost simultaneously in 1969. Clark’s ‘Happy Heart’ reached #12 on the Easy Listening chart and #62 on the Billboard Hot 100; Williams’ version peaked at #22 on the Billboard Hot 100, #19 in the UK, and spent two weeks at #1 on the Billboard Easy Listening chart. Clark was reportedly dismayed when Williams was a guest star on her second TV special, with the plan to perform ‘Happy Heart’ at the time each were planning to launch ‘Happy Heart’ as their next respective single.