FWIW. Since everyone else seems to be doing this.
1. There are n different types on labour.
2. Each individual has an endowment of one type of labour, and wants to trade some of it for some of the other types of labour.
3. But (double) coincidence of wants is rare, so they use money as a medium of exchange (and medium of account).
4. Output and employment are the same thing; prices and wages are the same thing.
5. Prices/wages are sticky. I don't really understand why, but I think it's probably got something to do with coordination problems.
6. Sometimes there is an excess supply of money, and money is a hot potato. It is easy to sell labour and hard to sell money. That causes prices/wages to rise.
7. Sometimes there is an excess demand for money, and money is a pleasantly warm potato on a cold night. It is hard to sell labour and easy to sell money. That causes the volume of trade to fall. We call that a recession.
8. Other economists with different types of labour can use different frameworks to talk about the long run, and other important things.