In few movies Same song will be rendered by two singers because of the situations like two different versions one by mother and other by child or one happy version or one sad version or sung by two different characters. Some examples

Dhoori Dhoori Dummakka dhoori" ( thendral sudum) -one by P.Susheela other by S,Janaki

Varusham maasam thethi paardthu - Mani Osai- one by P.Susheela other by S,Janaki

En kannil odum puthu vellam - Kaadu - one by P.Susheela other by S,Janaki

Mannil vandha Nilave - Nilave Malare -one by P.Susheela other by Shobha Chandrasekar.

muttathe mullayil - Olayil Ninnu -malayalam - one by P.Susheela other by S,Janaki

Kaaviri Nagarinil -vaazhnthu kaatukiren - one by P.Susheela other by Vani Jayaram

Many more can be listed.

But in Rare situation the same song is recorded by two singers and one will be placed in movie.

1. In "Manalane Mangaiyin Bhagyam" Movie there is a famous song "Thesulavuthe Then malarale" sung by Ghantasala and P.Susheela. In telugu also it was recorded with P.Susheela and later it was sung by Jikki because producer wanted to give atleast one song to Jikki who is his lucky mascot. It was informed to P.Susheela and She respected his sentiment and it was recorded with Jikki.

2. Recently I was watching a Telugu Interview of Smt. S,Janaki and the interviewer asked the rift between her and Savithri. She told " A beautiful melody was recorded by her for the movie "Padi thaanda Pathini" and Savithri told "I wont act if Janaki sings. I need P.Susheela's voice for me". So produced made P.Susheela to sing that song. Eventhough she given a hit like "singara velane deva", Savithri doesnt like to act with her voice. That was the issue. So not only the producers, the actresses also can change the singers. unfortunatley Both the versions are not available now.

3.Chinna gounder was remade in Telugu as "Chinna Rayudu" and the song "muthu mani maala" is also used in telugu version. P.Susheela Sang the Telugu Version and she went abroad for a program. After few days they have changed one line and because of unavailability of P.Susheela they made Chitra to sing that song.

Due to this kind of reasons the song will be released by two singers.I have found few rare songs like this.

1. chettulekkagalava oh narahari ( Chenchu Lakshmi) . One version is Sung by Ghantasala and Jikki and Other version is sung by P.B.Srinivas and P.Susheela.

Chettuleka gelava -P.Susheela - PBS

Chettulekkagalava - Jikki -Ghantasala

2.Omana Kaiyil oleevila (bharya -malayalam ).. Movie version is Sung by P.Susheela and there is another version sung by P.Leela. ( It was in LP record). I heared it before and dont have it now.