market price and equilibrium quantity

In recent years, technological improvements have greatly reduced the costs of producing music CDs, and a number of new firms have entered the music CD industry. At the same time, prices of substitutes for music CDs, such as Internet downloads and music DVDs, have declined considerably. Construct a supply and demand diagram of the market for music CDs. Illustrate the impacts of these developments, and evaluate the effects on the market price and equilibrium quantity.