He broke away from clichés in lyric writing and gave listeners sensible words to hum with songs like "Ladki kyon" and "Taare zameen par", but adman-turned-lyricist Prasoon Joshi says it was tough penning words for the Aamir Khan-starrer "Ghajini".

"Writing lyrics for 'Ghajini' was not an easy task simply because I was working on a thriller for the first time. The genre was something new for me and very different from my previous films, " Joshi told over telephone from Mumbai.

"The first thing I had to do was to get into the groove of the film. That took me a little bit of time. Once I understood the pace of the film, I started writing the lyrics, " he added.

The lyricist, who has worked with A.R. Rahman previously, teamed up with the musician yet again for the film and says it was a wonderful experience like always.

"I have worked with Rahman in many films and I can say that he is a very chilled out person. We cannot meet daily, but we share a great rapport and mutual understanding, so it's always great teaming up with him. I feel at home while working with Rahman, " said Joshi.

So which was the most challenging number in the album?

"Without a thought the most difficult song in the album has to be 'Behka behka'. Most importantly because Rahman does not follow any set structure when it comes to making a melody.

"At some places the song is very fast so I had to use appropriate words to match the tempo, " he explained. "Ghajini", which stars superstar Aamir Khan and south Indian actress Asin, is set to hit the screens Dec 25.

Joshi, who is currently associated with McCann-Erickson, has been behind various successful advertising campaigns including Coca-Cola, Cadbury and Close-up.

In 2001, he took up a parallel career as a lyricist with the movie "Lajja" and later went on to carve a niche for himself by writing the songs of "Hum Tum", "Rang De Basanti" and "Fanaa" among others.

Asked how he managed two careers, Joshi said: "I don't work with people who want me to write instantly. I have parallel careers so I need time to pen lyrics for a film. I mostly work in films when I get sufficient breaks from my advertising responsibilities."

Joshi admits that sometimes the workload is so much that he isn't able to spend enough time with family.

"Definitely you have to compromise on family time and you can't afford to be lazy. I've never done anything at the cost of anything else. So I make sure that my advertising work doesn't suffer because of my film commitments and vice-versa, " he added.

Joshi has also been part of various non-film albums with songs like "Ab ke sawan", "Man ke manjeere" and "Dooba dooba" among others. But his contribution to the non-film segment has been diminishing over the years.

"It's not that I don't want to do a non-film album. I love doing albums because I get more creative freedom and there are no constraints or limitations of the storyline.

"But the problem is that the market for private albums is shrinking. People now are more inclined towards film music. So that's why I now try and find my expression in Bollywood songs, " Joshi said.

With "Ghajini" songs becoming chartbusters, the lyricist's career is surely on an upswing. His upcoming projects include "Dilli 6" and "London Dreams". Bollywood actresses head to New Year parties outside Mumbai