想問Chopin Norturne op9 no 2(E flat minor)幾多級

In terms of technique, it should be around Grade 7 or 8 - it is not very difficult to manage, except perhaps the shimmering string of ornaments at the end. So if you are around Grade 8 or so, you should have no problem playing it.
Musically, it may be better played if you have had experiences playing other Romantic works as well as some knowledge of Harmony (around Grade 8 Theory). This is a very expressive nocturne, with a singing melody of the right hand while the left hand provides a discreet accompaniment with rich harmonies. The passion or emotion expressed requires a very sensitive performer, not to mention vivid creativitiy and imagination, as the main melody is repeated several times - there should be slight differences each time it is repeated so it wouldn't sound boring and dry.
If you have the Wiener Urtext edition of Chopin Nocturnes (edited by Jan Ekier, orange-red cover, shouldn't be expensive at Parsons or Tom Lee) you will also see a second version of this nocturne, which I find more interesting. I suggest trying this second version also, as it includes some additional ornamentations that are very interesting.
I remember seeing the ABRSM edition once, and I think they have edited the pedalling and slurs a bit and they are quite wrong. If you don't already have this book, try to avoid it and don't buy it.

It is in ATCL diploma.演奏級
Extended list of repertoire
for piano diplomas
from 2005
This list supplements the syllabus Diplomas in Music: Performance, Recital and Teaching
from 2005. It provides additional indicative repertoire for ATCL Recital Candidates for these examinations may now choose pieces from this extended list.
Programmes consisting exclusively of items drawn from this list do not need prior approval.
ATCL additional approved repertoire
Chopin:
Any of the following Nocturnes:
Op. 9: no. 1 in Bb minor; no. 2 in Eb; no. 3 in B
op. 15 no. 2 in F#; op. 32 no. 2 in Ab; op. 37 no. 2 in G;
op. 48 no. 2 in F# minor; op. 55 no. 1 in F minor; op. 62 no. 1 in B

ALBÉNIZ Navarra
J S BACH Italian Concerto (complete)
Prelude and Fugue in D minor, BWV 851 (Book 1, no. 6)
Prelude and Fugue in D minor, BWV 875 (Book 2, no .6)
Prelude and Fugue in Eb, BWV 852 (Book 1, no. 7)
Prelude and Fugue in F, BWV 880 (Book 2, no. 11)
Prelude and Fugue in F#, BWV 882 (Book 2, no. 13)
Prelude and Fugue in G minor, BWV 885 (Book 2, no. 16)
Prelude and Fugue in Ab, BWV 862 (Book 1, no. 17)
Prelude and Fugue in A, BWV 864 (Book 1, no. 19)
Prelude and Fugue in Bb minor, BWV 867 (Book 1, no. 22)
BARTÓK 2 Romanian Dances, op. 8a, Sz 43, I – Allegro Vivace, II – Poco Allegro
BEETHOVEN Sonata in F, op.10 no. 2
Sonata in C minor, op.13 (‘Pathetique’)
Sonata in C# minor, op. 27 no. 2 (‘Moonlight’)
Sonata in E minor, op. 90
BERKELEY Concert Study in Eb, op. 48 no. 2
BRAHMS Op. 116 no. 1 in D minor
Intermezzo in A minor, op. 118 no. 1
Ballade in G minor, op. 118 no. 3
Romance in F, op. 118 no.5
CHOPIN Any of the following Études:
Op. 10: no. 2 in A minor; no. 9 in F minor; no. 11 in Eb; no. 12 in C minor
Op. 25: no. 1 in Ab; no. 2 in F minor; no. 3 in F
HAYDN Sonata in C minor Hob XVI/20
Sonata in F Hob XVI/23
Sonata in E minor Hob XVI/34
Sonata in C Hob XVI/35
Sonata in D Hob XVI/37
Sonata in Bb Hob XVI/41
Sonata in Ab Hob XVI/46
Sonata in C Hob XVI/48
KABALEVSKY Preludes op. 38 nos. 5 and 6
DOUGLAS LILBURN From the Port Hills
LISZT Sonetto del Petrarca 123 (no.6 from Annees de Pelerinage 2nd year, Italy)
MENDELSSOHN Song Without Words in A, op. 38 no. 6
Song Without Words in G minor, op. 53 no. 3
MESSIAEN No. 4 (Regard de la Vierge) from Vingts regards sur l’enfant Jésus
MOSZKOWSKI Etincelles op. 36 no. 6

MOZART Variations on ’Ah! Vous dirai je maman’ K. 265
Sonata in A, K. 331
Sonata in F, K. 332
10 Variations on Unser Dummer Pobel meint K. 455
9 Variations on Minuet by Duport K. 573
POULENC 3 Pieces – Pastorale, Hymne,Toccata (complete)
Suite in C (complete)
PROKOFIEV Visions Fugitives op. 22 nos. 14 & 15 with some from 1–5
RACHMANINOV Prelude in D minor, op. 23 no. 3
Prelude in Eb, op. 23 no. 6
Polichinelle in F# minor, op. 3 no. 4 (from Cinq morceaux de fantaisie)
SCARLATTI Sonata in B minor, Kp. 27
Sonata in D, Kp. 491
Sonatas in G, Kp. 259/L. 103 & Kp. 260/L. 124
SCHUBERT Impromptu in Eb, op. 90 no. 2
Sonata in A minor,D. 537
Sonata in A,D. 664
Sonata in A minor,D. 845
SCRIABIN Poeme op. 32 nos. 1 and/or 2
Prelude in B minor op. 11 no. 6
Sonata-Fantaisie
SCULTHORPE Night Pieces (complete)
Sonatina
SHOSTAKOVICH Prelude & Fugue in A, op. 87 no. 7
Preludes op. 34 nos. 3, 5, 11 & 19 (all 4)
SINDING Rustle of Spring
TCHAIKOVSKY Dumka op. 59