CREATE TABLE table_66622 ("City of license" TEXT, "Identifier" TEXT, "Frequency" TEXT, "Power" TEXT, "Class" TEXT, "RECNet" TEXT)

What Class has a Frequency of 90.1 FM?
SELECT "Class" FROM table_66622 WHERE "Frequency" = '90.1 fm'
SELECT "Class" FROM "table_66622" WHERE "Frequency" = '90.1 fm'