§ 5.01. Purchase of art productions in certain cities. Cities of the first and second class are hereby authorized, in the discretion of those officers or bodies in such cities that have charge of the appropriation of the public funds, to purchase works of art which are the production of professional artists who are citizens of the United States, and which have been executed in the United States. The word "productions" shall be held to include among other works of art, mural paintings or decorations which artists may be employed to put on the walls of public buildings of such cities, mosaic and stained or painted glass. A city of the first class may expend under this section any amount not to exceed fifty thousand dollars annually. A city of the second class may expend under this section not to exceed ten thousand dollars annually.