Single on HMV (NZ), peaked at #1 in March 1968.
Popular New Zealand singer and TV star Mr Lee Grant, real name Bogdan Kominowski (b.1945) had six New Zealand hits 1967-68. He charted highly in NZ: they went 1, 1, 2, 1, 5, 6. Why Or Where Or When was one of three #1s, along with Thanks To You and Opportunity in 1967.
Adopting Mr to avoid confusion with an actress of the same name, Lee Grant became a pop superstar in New Zealand largely through his residency on the TV show C'mon 67. In 1968 he went to the UK, where he recorded some singles as Lee Grant (and one under his real name), but he eventually concentrated on acting. As Bogdan Kominowski he has been seen on stage (Phantom of the Opera), on TV (he had a continuing role in Brushstrokes) and in films (A View to Kill, Jack Ryan:Shadow Recruit): see his filmography at IMDb
Single on Columbia, November 1967, B-side of Why Can’t I Remember (To Forget You).
Before he became a star in 1960s Britain, Coventry’s Vince Hill (b.1937) had sung in the army (during national service), on the musical stage, and with a big band. Until he left to go solo in the early 60s, he had been in British vocal group The Raindrops along with Johnny Worth, aka songwriter Les Vandyke, writer of another #1 for Mr Lee Grant, Thanks To You.
Hill had nine records on the British Top 40, 1962-1971. The biggest was Eidelweiss, the Sound of Music song (1967, #2 UK), the song he is identified with in the UK.
Ernie Dunstall was Vince Hill’s regular arranger and accompanist.
Further reading: 1. Vince Hill biography al All Music by Dave Thompson: One of the most pleasing but now underrated of the many MOR heartthrob vocalists who assaulted the U.K. charts during the 1960s… 2. Ernie Dunstall portrait and commentary by David Roberts. 3. Ernie Dunstall discography at Discogs.com.
Not to be confused with "Why Or Where Or When" by Mr Lee Grant
Much-recorded song first heard in the 1937 musical Babes in Arms, sung by Ray Heatherton & Mitzi Green.
Further reading: Song history with many versions listed at The Originals.
Single on United Artists, B-side of Hold Me.
Italian-born operatic tenor Sergio Franchi (1926-1990) established a career in South Africa, Italy and Britain before moving permanently in the early 60s to the US where he became a star across several media and musical genres.
Further reading: Franchi’s long and varied career doesn’t lend itself well to a short summary. In this case, the Wikipedia article is a recommended source: detailed and properly footnoted.