Sospiri. Adagio for String Orchestra Op. 70 with Harp (or piano) and Harmonium (or organ) ad libitum Full Score
Elgar's last work for String Orchestra started out as an intended companion piece for his Salut d'amour, but the composer realised he was writing something more substantial, so he changed the scoring and the name.
A full score to go with these parts can be found at FMP 15062501