CREATE TABLE table_26216 ("Song 1 title" TEXT, "Artist 1" TEXT, "Song 2 title" TEXT, "Artist 2" TEXT, "Mix artist" TEXT, "Guitar part?" TEXT, "Level" TEXT)

Which level has marvin gaye as artist 1 and david bowie as artist 2?
SELECT "Level" FROM table_26216 WHERE "Artist 1" = 'Marvin Gaye' AND "Artist 2" = 'David Bowie'
SELECT "Level" FROM "table_26216" WHERE "Artist 1" = 'Marvin Gaye' AND "Artist 2" = 'David Bowie'