Questions regarding sight-reading

[indespair]

I require an explanation regarding sight-reading(I know what it exactly means) with the answers to the following questions:
1. Why is sight-reading considered to be important?
2. Is sight-reading a necessity to be a good performer or a composer in any way? I once heard something like many of the world's greatest pianists were not great sight-readers.
3. Can a great degree of sight-reading skill be achieved after a certain age? I ask because there is an age limit up to which a person can learn a language naturally- does anything like that apply to sight-reading?
4. If sight-reading is a necessity, how should one attempt to learn it? Where to start? I can read notes off a score any time but playing while going through it seems nearly impossible as it takes me some amount of time to put even the known notes together into a piece of music, let alone a piano piece I have never even heard before.

Any sort of advice regarding sight-reading is welcome. Thanks in advance.

[lostinidlewonder]

1) You can learn pieces faster so fast that you can literally play something you have never heard before at near mastery on first attempt just by sight reading. This saves a lot of time, instead of spending time memorizing you can skip that stage and use sight reading skills and produce the music immediately. Someone can hand you sheet music and ask you to play it and you can, this is a very empowering feeling, I remember before I could sight read people would always hand me sheets and I would shrug at them and say it will take me a while to learn first.

2) Performers do not need to be good sight readers unless they accompany others. A soloist can memorize a repertoire of 100 pieces and travel the world playing different combinations of it for the rest of their life. In that case they would never really become good sight readers because they have no need to learn new music. Performers who play a lot of music will need good reading skills or they will spent too much time studying music, there is more to do in life!!

3) I started serious study into sight reading as a late teenager and it took me about 15 years to get to a high level, although I do piano for a living. Sight reading is a skill you can practice but it requires good fingering understanding which requires good piano technique. Studying sight reading without understanding the art of fingering at the piano makes improvement difficult. Learn many pieces before you want to improve your reading, it is inefficient to seriously improve reading without a lot of piece experience from my own experience and teaching experience.

4) To respond in detail would require a personal answer, thus you need a teacher who is trained in sight reading teaching to sit with you and give you the best answer. Generally, our sight reading is always below our maximum playing ability. So learn to sight read a lot of easy piece without having to stop and take time to work things out. Slowly increase the difficulty of pieces you can fluently sight read. It can be difficult to humble yourself and start reading music many grades below your playing ability. It can be deceptively difficult to find the correct repertoire to improve your reading also, I have generally had a lot of good response from students studying to read Chorals with all the chord writing and pattern observations between chords.

[indespair]

That clears things up. Thank you.