CREATE TABLE table_9191 ("Date" TEXT, "Tournament" TEXT, "Surface" TEXT, "Partner" TEXT, "Opponents" TEXT, "Score" TEXT)

What type of surface was played on July 27, 2013?
SELECT "Surface" FROM table_9191 WHERE "Date" = 'july 27, 2013'
SELECT "Surface" FROM "table_9191" WHERE "Date" = 'july 27, 2013'