'''Symphony No. 5''' by Gustav Mahler was composed in 1901 and 1902, mostly during the summer months at Mahler's cottage at Maiernigg. Among its most distinctive features are the trumpet solo that opens the work with the same rhythmic motive as used in the opening of Beethoven's 5th symphony and the frequently performed Adagietto.
The musical canvas and emotional scope of the work, which lasts over an hour, are huge. The symphony is sometimes described as being in the key of C minor since the first movement is in this key (the finale, however, is in D major).'Gustav Mahler', in ''New Grove'', Macmillan, 1980 Mahler objected to the label: "From the order of the movements (where the usual first movement now comes second) it is difficult to speak of a key for the 'whole Symphony', and to avoid misunderstandings the key should best be omitted."Letter to ''Peters Music Publishers'' dated July 23, 1904. Cited after: http://www.gustav-mahler.org/gesamtausgabe/berichte/cr5-f.cfm