"(It Will Have to Do) Until the Real Thing Comes Along" is a popular song first published in 1936.

According to one version of the original sheet music, the songwriting credits read: "Words and Music by Sammy Cahn, Saul Chaplin and L.E. Freeman".

Another version has, immediately below the title, the words: "with Piano Accordion". According to this version, the songwriting credits read: Words and Music by Mann Holiner, Alberta Nichols, Sammy Cahn, Saul Chaplin and L.E. Freeman.

Otherwise, graphically, the two versions are identical.

source:  http://en.wikipedia.org/wiki/Until_the_Real_Thing_Comes_Along

Billie Holiday (born Eleanora Harris^[1][4] April 7, 1915 – July 17, 1959) was an American jazz singer and songwriter. Nicknamed "Lady Day" by her friend and musical partner Lester Young, Holiday had a seminal influence on jazz and pop singing. Her vocal style, strongly inspired by jazz instrumentalists, pioneered a new way of manipulating phrasing and tempo.

Critic John Bush wrote that Holiday "changed the art of American pop vocals forever."^[5] She co-wrote only a few songs, but several of them have become jazz standards, notably "God Bless the Child", "Don't Explain", "Fine and Mellow", and "Lady Sings the Blues". She also became famous for singing "Easy Living", "Good Morning Heartache", and "Strange Fruit", a protest song which became one of her standards and was made famous with her 1939 recording.

http://en.wikipedia.org/wiki/Billie_Holiday

Real enough. Especially as Lady Day expresses it in that inimitable bluesy, "slow & rough" vocal style. She knew...

Until the Real Thing Comes Along

I'd work for you
I'd slave for you
I'd be a beggar or a knave for you
If that isn't love, it will have to do
Until the real thing comes along

I'd gladly move
The earth for you
To prove my love, dear
And its worth for you
If that isn't love, it will have to do
Until the real thing comes along.

With all the words, dear, at my command
I just can't make you understand
I'll always love you darling
Come what may
My heart is yours
What more can I say?

I'd lie for you
I'd sigh for you
I'd tear the stars down from the sky for you
If that isn't love, it will have to do
Until the real thing comes along

With all the words, dear, at my command
I just can't make you understand
I'll always love you baby
Come what may
My heart is yours
What more can I say?

I'd lie for you
I'd cry for you
I'd lay my body down and die tor you
If that isn't love, it will have to do
Until the real thing comes along