CREATE TABLE table_42632 ("Rank" FLOAT, "Song title" TEXT, "Composer ( s ) " TEXT, "Performer ( s ) " TEXT, "Year" FLOAT)

How many years was Louis Armstrong performing?
SELECT COUNT("Year") FROM table_42632 WHERE "Performer(s)" = 'louis armstrong'
SELECT COUNT("Year") FROM "table_42632" WHERE "Performer(s)" = 'louis armstrong'