There are certain songs, that when they were released for the first time, they failed to make any commercial impact, and when some other artist makes a cover of this song, and becomes a big hit, then most people believe the cover is actually the original! The songs below are such examples.
(Songs in alphabetical order)
1) A Groovy Kind Of Love by Diane & Annita (1965) (became popular by The Mindbenders in 1965)
Apart from The Mindbenders' version, It became popular once again in 1988, when Phil Collins did a cover of it. The original version is totally unknown as well as the artists who released it first.
2) Alone by I-Ten (1983) (became popular by Heart in 1987)
Personally I like Heart's version better, only because I believe this song suits a female vocalist more. But of course I-Ten's version isn't bad either. Interestingly, from the same album (Taking A Cold Look), two other songs were covered by Honeymoon Suite and REO Speedwagon. The title track and I Don't Wanna Lose You respectively. But it was Alone that made it to #1 in the US charts.
3) Black Betty by Unknown (circa early 20th century) (became popular by Ram Jam in 1977)
It was Ram Jam who brought this marching song to the masses in a Hard Rock version. According to this YouTube video it was recorded in a Texas Prison in 1933. Still it doesn't mean 1933 is the year when this song was sung for the first time.
4) Cryin' by Jeff Paris (1987) (became popular by Vixen in 1988)
Jeff Paris is an unfairly forgotten musician who released two good solo albums in 1986 and 1987. Race To Paradise and Wired Up. The latter contained the song Cryin' which almost reached the US Top 20 when it was covered by the female Glam Metal band Vixen. I'd pick Jeff Paris' version here though.
5) Hold On by Ian Thomas (1981) (became popular by Santana in 1982)
I would consider Ian Thomas' version better, but unfortunately not many people are aware that Hold On was originally not a Santana's song.
6) House Of The Rising Sun by Unknown (became popular by The Animals in 1964)
It was The Animals who made this traditional song known to public. Origins of the song are unknown, as it happens with songs which existed before recording techniques began to exist. The first recorded version of this song, was by Tom Clarence Ashley & Gwen Foster in 1933. Another notable version is Bob Dylan's version in his debut album in 1962. Only two years before The Animals made it a hit.
7) Hush by Billy Joe Royal (1967) (became popular by Deep Purple in 1968)
Although Billy Joe Royal's version was a moderate hit already (peaking at #52 in the US chart), it was Deep Purple who made the song a big hit peaking at #4 in the US chart and #2 in Canada. And after all those years it's Deep Purple's version that it's remembered, whilst Billy Joe Royal's version is more forgotten.
8. I Wanna Go Back by Billy Satellite (1984) (became popular by Eddie Money in 1986)
Billy Satellite were an one album band who had minor success in the mid 80s. Their album was one of those gems that lost in obscurity. A real classic AOR album with Southern Rock influences. Two of their songs later covered by Eddie Money, I Wanna Go Back and Satisfy Me much later. I Wanna Go Back was a Top 20 hit for Eddie Money.
9) In The Army Now by Bolland & Bolland (1982) (became popular by Status Quo in 1986)
The original version by Bolland & Bolland was a mega hit in Scandinavian countries, reaching #1 in Finland and in Norway, and #2 in Sweden, yet unknown to other countries. It was Status Quo that made this song a big hit all across Europe in 1986. Although it was a big hit in Europe, it failed to make any impact in the US. Status Quo version sounds better though. The original sounds incomplete for some reason.
10) Only The Young by Scandal (1984) (became popular by Journey in 1985)
I cannot say, whether we could call it a cover or not, and who covered who, but I believe we should go with who released the song first. The song was released first in Scandal's album Warrior, without any commercial success. When Journey released this song, it became a Top 10 hit. Personally I prefer Journey's version.
11) Since You've Been Gone by Russ Ballard (1976) (became popular by Rainbow in 1979)
Later it was covered by many artists as well. Russ Ballard wrote songs from many other popular artists by the way. Such examples are I Surrender (sung by Rainbow), On The Rebound (sung by Uriah Heep, and also included in his 1980 album Barnet Dogs), You Can Do Magic (sung by America), etc.
12) Tainted Love by Gloria Jones (1964) (became popular by Soft Cell in 1981)
I really wonder how someone feels, if you record a song fails to chart...and more than a decade later someone else sings your forgotten by God song, and turns it into a smash hit. Tainted Love is one of those cases.
13) The Best by Bonnie Tyler (1988) (became popular by Tina Turner in 1989)
Although Bonnie Tyler's version was a Top 10 hit in Norway when it was released, it was Tina Turner's version that was a worldwide hit. Bonnie Tyler's version became known after Tina Turner made it a hit, and many thought it was a cover, but actually it was the first version.
14) Torn by Ednaswap (1994) (became popular by Natalie Imbruglia in 1997)
To be honest, I don't like any of the versions, not my style. But still it's surprising the fact that it wasn't sung by Natalie Imbruglia, since it's her signature song.
15) You Can Leave Your Hat On by Randy Newman (1972) (became popular by Joe Cocker in 1986)
Whilst not a commercial success, this song became famous mostly because of the striptease scene in the movie 9 1/2 Weeks. Still in our days it's used as a striptease song very often, and it's Joe Cocker's version that it's been used all those years.