CREATE TABLE table_2921 ("Song 1 title" TEXT, "Artist 1" TEXT, "Song 2 title" TEXT, "Artist 2" TEXT, "Mix artist" TEXT, "Guitar part?" TEXT, "Mix pack" TEXT, "Release date" TEXT)

If artist 1 is Wolfgang Gartner, what is the release date?
SELECT "Release date" FROM table_2921 WHERE "Artist 1" = 'Wolfgang Gartner'
SELECT "Release date" FROM "table_2921" WHERE "Artist 1" = 'Wolfgang Gartner'