They are at least three groups with the name Soluna.
One is an Argentinian rock/folk group formed in 1976, another is an American pop group lead by Hispanic women, and the other is German goa/psytrance producer Volker Dornemann.

1976 Soluna: They were formed by Gustavo Santaolalla as soon as his other band Arco Iris disbanded. They recorded their sole album in 1977, "Energia Natural" (Natural Energy).
The album was well received by critics and public alike. Santaolalla decided to move to the United States during their greatest moment and thus the band was dissolved.

1998 Soluna: Soluna began in 1998 when Aurora Rodriguez and America Olivo, who had become friends while both attending California Institute of the Arts, met up after a few years apart. The two met with a record producer friend and found Jessica Castellanos, another aspiring singer. The three started singing together but sought a fourth member to complete the group. By chance, another producer recommended to them a young girl he'd met while driving in Ontario, California. He had stopped at a local auto-body shop due to car trouble and saw the owner's daughter's picture on the wall. The girl's father assured him his daughter was talented and could sing. Her name was Christina "T" Lopez, and after singing "Amazing Grace" over the phone, she became the final member of Soluna. Shortly after their line-up was complete, Soluna signed with DreamWorks Records.