CREATE TABLE table_56521 ("Home team" TEXT, "Home team score" TEXT, "Away team" TEXT, "Away team score" TEXT, "Venue" TEXT, "Crowd" FLOAT, "Date" TEXT)

What away team did Melbourne play as the home team?
SELECT "Away team" FROM table_56521 WHERE "Home team" = 'melbourne'
SELECT "Away team" FROM "table_56521" WHERE "Home team" = 'melbourne'