There is more than one artist with this name:

1) Viva is a German Heavy Metal Band hailing from Hanover. They formed in 1980 and are still kicking. Their work consists of Blue Jeans Forever EP, 1980
Born To Rock Full-length, 1980
What The Hell Is Going On Full-length, 1981
Dealers Of The Night Full-length, 1982
Apocalypse Full-length, 1984
Cream Cake Box Full-length, 1996
Encyclopaedia Metallum for more info about current and former members.

2) Viva is an all girls band which was formed as a result of a talent hunt organised by Channel V in 2002. The band had five members who were Seema Ramchandani, Pratichee Mohapatra, Neha Bhasin, Mahua Kamat and Anushka Manchanda. Their first album was the self titled 'Viva' which was a moderate hit. Seema left soon after the launch of their first album. Another album 'Relaoded' was released in 2003. It wasnt a success.. and the gropu members parted ways with some of them pursuing individual careers, with Pratichee releasing her solo album and anushka trying her hand in Tamil and Telugu music industry.

3) Viva is Spanish EuroDance artist.

Viva's first song Nirvana was released in Spain, and quickly became a # 1 song on the Billboard charts and remained #1 for 6 consecutive weeks.
Nirvana was released under Edel records in Germany. Viva's second song Keep On Dreaming also became a radio hit throughout Central America,
reaching the # 1 spot on the radio play lists. And still remains in the top 10 most solicited songs.

Official Homepage

4) Viva is an indie rock band from Athens, Georgia.

Viva's first song Nirvana was released in Spain, and quickly became a # 1 song on the Billboard charts and remained #1 for 6 consecutive weeks.
Nirvana was released under Edel records in Germany. Viva's second song Keep On Dreaming also became a radio hit throughout Central America,
reaching the # 1 spot on the radio play lists. And still remains in the top 10 most solicited songs.

Official Homepage