if you don't get any errors, try changing the parameter 'galselect' to something where you know you will get some rows returned, at least then you know your syntax is ok.
Thinking about this though, is your query asking the right question ?
At the moment, using your 'LIKE' you are looking for Category to include the string ''Seascapes Elvis ZZ Top"
Are you looking for Category to include "Seascapes" OR "Elvis" OR "ZZ Top" ?, in which case, investigate using the mySQL IN clause, something like..
"SELECT Category FROM products WHERE Category IN ('Seascapes', 'Elvis', 'ZZ Top')"