I my self have always preferred learning by ear to sheet music. I wasn't brought up in a royal conservatory type program and I was quite intimidated by it until I had to learn in order to be accepted into Berklee. I had this stigma with sheet music that it was for boring classical players. It is like a whole other language and I had always heard that the ideal age to learn a new language is 5 - 9. I felt as though I was too late. It was a daunting and intimidating challenge, but now I have a new appreciation for it.
1. Learning Accurately
When you learn a piece off of well - sourced scores, you know for a fact that you are learning each part note for note. When learning by ear, we can incorrectly interpret a melody or phrase.
2. All Dynamics, Timing & Details Notated
Sometimes with learning a song by ear or less concrete methods, we can have issues with dynamics, timing and details. In notation, symbols like forte, piano, staccato etc. help us pay attention to detail. On the paper you also plainly have the time signature, bpm and note values. You don't have to listen and wonder "is that a quarter note or an eight note?" It's right there so you can easily break down the rhythms measure by measure.
3. Better Understanding of Theory
Theory is taught and visually demonstrated with notation. You never really learn the full language until you learn how to read music. Once you begin to study aspects of theory it is quite fun. It is like figuring out a secret code or something. Not knowing notation has a huge impact on your communication skills with other musicians.
4. Quick Learning Method
Ah yes, so many students ask me if I can pull out a piece of music and play it right away. The answer for me is no. However, with a long history of notation literacy and practice, many can. Sheet music can be a very quick shortcut to learning a piece at your skill level. I my self marvel at those who have mastered sight reading.
5. Can Play with out Hearing
Because all of the information is there in detail, though I don't recommend it, you can learn songs with out listening to them first. It's a useful skill in a scenario such as "our pianist had to leave suddenly for a family emergency. Can you play the piece for the ceremony?!" It's a good thing to have if you are ever put on the spot.
1. Paper Dependent
You have come to the point where you can not go anywhere with out a big thick binder of disorganized mis- hole punched music scores that where printed off of illegal websites.. phew. One thing that is nice about learning by ear is that you keep the songs you know with in you. You are your own library and are ready to go at any time!
2. Disconnect of Audiation
As I mentioned earlier, you could learn a piece off of sheet music with out even hearing it first. The problem with this is it causes a mass disconnect from audiation. If some one asked you to hum the melody of the song you are learning, you would struggle. Musicians that learn by ear audiate the song in their head 91% more frequently than those that don't. They have a complete view of the song as a whole and a better instinct to where it's going next. This is why it's important to give your student the correct resources before they start a new song. Refer them to an audio clip or at least demonstrate it for them.
3. Little Confidence in Improvisation
Unfortunately it is very common for a lot of classically trained musicians to not have any confidence in their ability to improvise. Ask your students to improvise every now and than. Show them how to apply what they learn in their own way. Take major scales for example, show them how they can rearrange those notes and create melodies!