CREATE TABLE table_70727 ("Artist" TEXT, "Country of origin" TEXT, "Period active" TEXT, "Release-year of first charted record" FLOAT, "Genre" TEXT, "Claimed sales" TEXT)

What is the Genre, when the Release-year of first charted record is 1968, and when the Country of origin is United States?
SELECT "Genre" FROM table_70727 WHERE "Release-year of first charted record" = '1968' AND "Country of origin" = 'united states'
SELECT "Genre" FROM "table_70727" WHERE "Country of origin" = 'united states' AND "Release-year of first charted record" = '1968'