Ear training serves to aid musicians develop their musical skills. Musicianship is an essential quality of good musicians. Ear training helps musicians understand their music and can help us learn new music more efficiently. Ear training is especially important to composers, who can easier translate their ideas to score if they have a better understanding of music.
The two main types of ear training are rhythmic and melodic. Melodic ear training has several components. The first aural skill most musicians learn is interval ear training, or the ability to recognize the distance between two notes. Intervals have a quality and a size, such as a major third or a perfect fifth. Knowledge of scales is another aural skill musicians need to develop. The most common scale types musicians need to know are major and minor scales. Musicians also learn the differences between chords, including major, minor, diminished and augmented triads, seventh chords (major, minor, diminished and half-diminished) and chord progressions called cadences. Musicians learn how to dictate music that they hear, and they also learn how to sight-sing, or to produce what music they see with their voices.
The benefits of melodic ear training include being able to better understand music and to recreate music you hear. For instance, composers who hear what they want their music to sound like in their heads can translate that information into musical notation much easier if they have had melodic ear training. Musicians studying a piece of music can understand the composer's intentions if they can hear the cadences or intervals used in the piece.
Melodic ear training builds musicianship--musicians can learn new music quickly and understand better what the composer wanted the music to sound like, thus improving performance of the music.
Melodic ear training takes time and practice. Musicians who begin ear training at a young age, around four or five, have a better chance of having perfect pitch, or the ability to hear and identify pitches almost instantly. Most musicians who do not have perfect pitch can acquire relative pitch, or the ability to tell the difference between notes and chords, with practice. Even though ear training takes practice and effort, it is a beneficial and rewarding musical skill to acquire.