Robin Thicke says the passing of his father in 2016 ''rattled his soul''.

The 41-year-old singer was left heartbroken when his father Alan Thicke passed away two years ago in December 2016, and has said he was left so shaken by the tragedy that he cancelled plans to release an album and went back to the drawing board to pen songs with ''more meaning''.

He said: ''Well, it's funny - my father passed away a couple of years ago and I thought I had an album and these songs that I wanted to put out. Then when that happened, it was something I wasn't expecting and it just rattled my soul. So, I took some time to re-think the album and then these songs started pouring out that had more meaning and more weight to them.''

Robin released his first single in two years on Wednesday (12.12.18) in the form of 'Testify', which deals with his father's sudden heart attack which ultimately caused his death at the age of 69.

In the song, Robin sings: ''It was the perfect day/And everything changed/I lost my father suddenly/Couldn't keep it together, my family/And all my reckless ways caught up with me.''

And the 'Blurred Lines' hitmaker - who has son Julian, eight, with former spouse Paula Patton, as well as daughter Mia, nine months, with his girlfriend April Love Geary, whom is currently pregnant with their second child - admits it was ''cathartic'' for him to be able to put his thoughts into song.

Speaking to Zane Lowe on Apple Music's Beats 1 radio, he said: ''It's cathartic just to be able to say it and then let it live, as opposed to in the middle of a conversation or a quote.

''Once you put it into song form, then it can live forever. And so the message in the song is really about the hope and the light at the end of that tunnel when you feel that you lost or you feel that you don't know what to do next. You know, that reconnection to God or spirituality or something deeper than the surface is what brings you back home to who you really are and who you want to be.''