Notwithstanding any other provision of law to the contrary,

Section shall not apply to any elementary school district, high school district, or unified school district, which maintains no individual class session with pupils in attendance exceeding the numbers, for the particular grade levels, following: (

a) An elementary school district—twenty-eight (28) pupils. (

b) A high school district—twenty-five (25) pupils. (

c) A unified school district—twenty-eight (28) pupils in respect to grades kindergarten through 8, inclusive; and twenty-five (25) pupils in respect to grades through 12, inclusive. As used in this

section the phrase “individual class session” shall not include any class session held in grades kindergarten through 8, inclusive, in courses in visual and performing arts, industrial arts, and physical education. The phrase shall not include any class session held in grades through 12, inclusive, in courses in commercial arts, visual and performing arts, industrial arts, vocational arts, and physical education. The phrase “individual class session” shall not include any class session held in grades through 12, inclusive, for which two or more individual class groups which come within the descriptions specified by the first paragraph of this

section and subdivision (

a) or (b), or both, are assembled together in the same room for joint lectures or demonstrations. Notwithstanding the provisions of subdivisions (

b) and (c), grades 7, 8, and of a junior high school shall be deemed to be high school grades for purposes of this section.