Once hailed as the heir to Lata Mangeshkar's throne, Alka Yagnik has delivered songs that deliver on the promise. As the singer turns 51 today (20 March), we take a look at 10 songs that define her iconic presence through Hindi cinema. 

1. 'Ek Do Teen' – Tezaab (1988)

The ultimate 'item number', the song launched the Madhuri mania across India. The voice behind the dazzling dancer was Yagnik. A relatively unknown singer, 'Ek Do Teen' launched Yagnik into the stratosphere. It was also the film that launched another sensation, Madhuri Dixit. Decades later, it is this song that remains the most memorable moment in the actress' career, and Yagnik's as well. 

2. 'Gazab Ka Hai Din' – Qayamat Se Qayamat Tak (1988)

It was in Nasir Hussain's Romeo-Juliet saga that Yagnik proved her calibre. If there was a singer who could convey the innocence and optimism of Juhi Chawla, it was Yagnik. 'Gazab Ka Hai Din' is a beautiful number that resonates with young love even today. With Chawla and Aamir Khan, Qayamat Se Qayamat Tak went on to become a landmark in Indian cinema. With it, the singer had well and truly become the leading voice of the 1990s. 

When Qayamat Se Qayamat Tak was called Nafrat Ke Waris

3. 'Waada Raha Sanam' – Khiladi (1992)

In the 1990s when white canvas shoes and Khiladi was still not a synonym for Akshay Kumar, Yagnik soared with this beautiful melody composed by Jatin-Lalit. It was singer Abhijeet's Bhattacharya's debut song, but Yagnik just about stole his thunder. This wonderful duet remains one of the iconic songs of the 1990s nostalgia, complete with white jackets, canvas shoes, and the Matheran location. 

4. 'Kuch Kuch Hota Hai' – Kuch Kuch Hota Hai (1998)

There is no need to explain this song. One of the biggest hits of the decade, and a film that would redefine love for an entire generation of filmgoers, Kuch Kuch Hota Hai had Yagnik singing along to Jatin-Lalit's fabulous title composition. The song won her the National Award in 1998. For Karan Johar, Yagnik remains the lucky charm. He has used her voice in every one of his films since. 

5. 'Suraj Hua Maddham' – Kabhi Khushi Kabhie Gham... (2001)

Speaking of chemistry, Kajol and Shah Rukh Khan raised the temperature on screen with this gorgeously shot song in Kabhi Khushi Kabhie Gham... Yagnik added the perfect touch of sensuousness and silk to make Kajol sound irresistible. Sadly, it never won Yagnik an award, although Sonu Nigam won the Filmfare award for Best Male Playback singer. 

6. 'Tauba Tumhare' – Chalte Chalte (2003)

After a brief pause in hits, the singer returned with a bang in the Shah Rukh Khan-Rani Mukherji-starrer Chalte Chalte (2003). The film had three male voices — Udit Narayan, Abhijeet Bhattacharya and Sukhwinder Singh. But only one female voice —  Yagnik. That says it all! 

7. 'Chand Chupa Badal Mein' – Hum Dil De Chuke Sanam (1999)

Yagnik was a part of Sanjay Leela Bhansali's most musical films — Khamoshi: The Musical (1996), Saawariya (2007) and Hum Dil De Chuke Sanam (1999). This song takes precedence for its melodious quality and the chemistry between the voices of Yagnik and Udit Narayan, which rivalled those of the actors onscreen. 

8. 'Taal Se taal Mila' – Taal (1999)

Yagnik shares a splendid rapport with AR Rahman. The Mozart of Madras has created some superb compositions for the versatile singer, which stand the test of time. One of them is this brilliant symphony for Subhash Ghai's musical hit Taal (1994). The film won Yagnik her third Filmfare Award for Best Playback Singer in 2000. 

9. 'O Re Chhori' – Lagaan (2001)

10. 'Agar Tum Ho' – Tamasha (2015)

Just when the film industry was beginning to forget the songstress, she returned with this melancholic ballad. In a film that was replete with stunning music, 'Agar Tum Saath Ho' and Yagnik's voice linger long after others have faded. From Madhuri Dixit to Deepika Padukone, the singer continues to go strong into her 51st year.