我想知依3隻歌GE簡介,,,,急!!!

1) Piano Sonata in E-Flat, HOB XVI No.49 by Joseph Haydn :
Among the late Haydn Sonatas, No. 49 in E-Flat merits special attention. Haydn composed it in 1789-1790 for his friend, Marianne von Genzinger, telling her that it "may be given out to no one else." But to his surprise, the sonata leaked out and found its way into print. He later wrote to her, "What a pity Your Grace does not own a Fortepiano by Schanz since everything is expressed better on it." The music is indeed more suited to that instrument since it demands quick changes of dynamics and marked accents which are impossible to perform on a harpsichord.
The Adagio cantabile movement, in B-Flat Major, has a stormy middle section in B-Flat minor in which the right hand continues its arabesques while the left hand must cross from deep in the bass to the upper reaches of the keyboard. This is a feature that Frau von Genzinger asked Haydn to change because it exceeded her technical ability.

For more details, please ref :
http://www.carolinaclassical.com/articles/haydn.html


2) Étude Op.25, No,1 in A Flat Major by Frédéric Chopin. :
Étude Op. 25, No. 1 is a solo piano work composed by Frédéric Chopin in 1838. This work consists entirely of rapid arpeggios and harmonic modulations based on A-flat major. Robert Schumann famously praised this work in a dissertation on the Études. Stating that the arpeggios were "fantastic", and the "wondrous" melody, it was Schumann who coined the alternate name "Aeolian Harp" for this étude....

For more details, please ref :
http://en.wikipedia.org/wiki/%C3%89tude_Op._25%2C_No._1_%28Chopin%29


3) Four Impromptus Opus 90 D. 899 by Franz Schubert
Franz Schubert's Impromptus, Opp. 90 and 142 (post.), are a series of pieces for solo piano which were composed in 1827 and first published during the composer's lifetime (or shortly thereafter) under that name. There are eight such Impromptus in total.
Four Impromptus, Op. 90 (D. 899)
The Opus 90 impromptus consist of 4 typical romantic-era pieces, each with distinct elements....

For more details, please ref :
http://en.wikipedia.org/wiki/Impromptus_%28Schubert%29#Four_Impromptus.2C_Op._90_.28D._899.29