Guitar lessons on scales and modes. There are 5 basic scale shapes that every guitar player should know. They should be practiced and played daily in all positions. A question I get asked alot is "Do I really need to learn scales?" The answer is "Yes". Knowledge of the basic scales (major, minor, and pentatonic) and when to use them are an essential ingredient to becoming a great guitar player. Scales are essential if you want to be able to pick up a guitar and jam with almost any song.