There are multiple artists with this name:

1) Alda is a collective project dedicated to the reclamation of Lost Wisdom and the application of a lifestyle founded on respect and communication with the soils on which they dwell. They are currently based out of the Tahoma landscape within the Cascade Mountain Range. They play a style of black metal that is considered to be of the Cascadian ilk with influences deriving primarily from Windir, Burzum, Agalloch, Ulver and Drudkh. Official sites: http://www.facebook.com/pages/Alda/116289091792839 - http://www.myspace.com/aldacascadia

2) Alda (Alda Björk Ólafsdóttir) is an Icelandic pop singer who scored two Top 20 UK hits in 1998 with '"eal Good Time" and "Girls NIght Out". "Real Good Time" was covered by Aaron Carter and also South African Pop Idol winnner Anke Pietrengeli. Other artists in Italy, Spain and Asia have also recorded her songs and apart from the double platinum disc from North America she was also awarded a Gold Disc in Canada, Indonesia and the UK. Alda is still recording music and you can hear some of it on her official Myspace: http://www.myspace.com/aldamusic

3) Alda (Alda Risma Elfariani) is a pop singer from Indonesia, he became popular because of his song titled "Aku Tak Biasa". Alda also had a duet with boy band Code Red in the song "We Can Make It".