CREATE TABLE band (id DECIMAL, firstname TEXT, lastname TEXT)
CREATE TABLE vocals (songid DECIMAL, bandmate DECIMAL, type TEXT)
CREATE TABLE albums (aid DECIMAL, title TEXT, year DECIMAL, label TEXT, type TEXT)
CREATE TABLE tracklists (albumid DECIMAL, position DECIMAL, songid DECIMAL)
CREATE TABLE performance (songid DECIMAL, bandmate DECIMAL, stageposition TEXT)
CREATE TABLE instruments (songid DECIMAL, bandmateid DECIMAL, instrument TEXT)
CREATE TABLE songs (songid DECIMAL, title TEXT)

What are all the instruments used?
SELECT DISTINCT instrument FROM instruments
SELECT DISTINCT "instrument" FROM "instruments"