Rihanna

The parties had to be kept quiet so Rihanna could save her weakened voice on her recent 777 tour.

The 'Diamonds' singer was accompanied by a team of media as she travelled to seven countries in seven days to launch her latest album, 'Unapologetic', and although she came under fire for not partying on the plane, she says it was for professional reasons.

She told the UK's BBC Radio1: ''It was different having to do your job but also have 200 guests come along with you.

''I knew I had seven countries and seven shows and I had to save my voice.

''I didn't go crazy. I didn't party too hard. I did have fun though. I tried to get everybody involved but sometimes you just wish you could give more.''

Rihanna, 24, also said she spent most of her time on the special Boeing 777 jet - which travelled from Los Angeles to Mexico City, Toronto, Stockholm, Paris, Berlin, London and finally, New York - getting much needed sleep between stops.

She added: ''They all want you to host a party every time you get on the plane after a show but you really only have that time to sleep until you get to the next country. ''Sometimes it was a two-hour ride to the next country and that was all the sleep you would get.

''I like to push through the tiredness and I go and go and go. But I'm starting to learn now that I have to take it easy.''

© Bang Showbiz