I offer two LED music-stand lights of the Mighty Bright brand.  Each shines at two different level of brightness and runs either plugged in or on 3 AA batteries.  (I keep the batteries in a separate plastic bag, so they don't leak during long periods of nonuse and spoil the contacts.)  You can get brighter lights these days for $30, with lithium-ion batteries.  But these would meet the needs of many musicians.