CREATE TABLE table_15559 ("Date" TEXT, "Opponent" TEXT, "Score" TEXT, "Loss" TEXT, "Attendance" FLOAT, "Record" TEXT)

Who was the opponent in the game where the attendance was larger than 23,230 and the record was 56-37?
SELECT "Opponent" FROM table_15559 WHERE "Attendance" > '23,230' AND "Record" = '56-37'
SELECT "Opponent" FROM "table_15559" WHERE "Attendance" > '23,230' AND "Record" = '56-37'