old school

Short definition from Wiktionary

Noun

1. 1
   Preceded by the: a group of people characterized by being conservative or traditional; also, a method for accomplishing a task, a style, or a way of thinking that was employed in a former era, remembered either for its inferiority to the current method, or for its superiority over the new way.
2. 2
   A style of popular music regarded as more old-fashioned or traditional, or not following newer trends; specifically (often old skool), hip-hop or rap music of the late 1970s and 1980s (or more recent music of this style) as contrasted with newer styles of such music.

Adjective

1. 1
   Now often old-school: characteristic of a method for accomplishing a task, a style, or a way of thinking that was employed in a former era, remembered either for its inferiority to the current method, or for its superiority over the new way.
2. 2
   Of or relating to a style of popular music regarded as more old-fashioned or traditional, or not following newer trends; specifically (often old skool), of or relating to hip-hop or rap music of the late 1970s and 1980s (or more recent music of this style) as contrasted with newer styles of such music.
3. 3
   Chiefly in the form Old School: having conservative or traditional views on Christianity or politics.
4. 4
   Alternative form of old school.
5. 5
   Alternative letter-case form of old school (“having conservative or traditional views on Christianity or politics”).