Melodic dictation (also called transcription) involves the ability to hear a piece of music and quickly play it back or write down the notes of the melody. One of the main goals of ear training is to strengthen your powers of visualization - being able to hear a phrase and immediately visualize how it will look and feel when played on your instrument. Melodic dictation is closely tied to visualization, and is a skill that most experienced improvisers and composers have developed to a high degree.
To begin building this important skill, start with very short fragments - three or four notes of a simple melody. Try to sing the phrase and convert the tones of the melody to scale numbers. Visualize how the melody will look and feel on your instrument. Soon you will be ready to move on to longer, more complex phrases. Notice how the longer phrases are often made up of shorter melodic patterns that you already know. As your ability increases, you will eventually be able to mentally practice and compose music away from your instrument.
Parrot Phrases will greatly increase your visualization skills. By regularly training your ear with this game, you will soon be able to mentally 'see' exactly how to play all kinds of melodies on a piano or guitar.