Although the ideas in it had doubtless been gestating for some time, Enescu began writing the Fifth Symphony during his annual summer break at his villa, Luminiș, in Sinaia in 1941, completing the entire draft in a span of something less than one month.

[1] At some later date (perhaps in Romania before September 1946, or later, in Paris), Enescu set about the orchestration, completing twenty-five pages (about two-thirds) of the first movement, up to a culminating chord in the fifth bar of the recapitulation.

Realizing that the orchestrational integrity of the whole would otherwise suffer, Bentoiu (with Țăranu's agreement) reworked the entire finale as well as the unfinished third of the first movement, and the completed symphony was finally premiered in Bucharest by the Romanian National Orchestra and Radio Choir, with Florin Diaconescu, tenor soloist, conducted by Horia Andreescu [ro], on the opening concert of the 1996–97 season.

[5] It involves a broadening of the concept of cyclic form, however, in that the allocation of roles for the various themes is constantly changing, in a sort of perpetual variational thinking.

[6] The first thematic group is striking for the breadth of its melodic content, which is not usual for any symphony, and is not found in Enescu's previous four essays in the form.

[1] Structurally, the movement is extremely free, beginning with a series of thematic expositions in an A B A' B' C D sequence, then continuing from rehearsal 32 with only the material already presented up to that point.

After a dense opening passage, the texture gradually thins out, eventually giving way to a sort of chorale (taking the place of the conventional trio section), though with continuing bursts from the first theme.

[11] The finale (Andante grave) is an extended cantata for tenor solo, female choir, and orchestra, using as text an early variant of the poem "Mai am un singur dor" (I Have but One Desire) by Mihai Eminescu.

The effect is funereal (in his edition, Bentoiu has taken the liberty of adding to the tempo marking, in brackets, "Quasi marcia funebre"), implacable, rigid, and magnificent.

[13] The text used in the last movement of the symphony does not quite correspond to any of the four "official" versions of Eminescu's poem, but is based on an early variant beginning with the words "De-oi adormi curând / În noaptea uitării / Să mă duceţi tăcând, / La marginea mării" (When soon I'm laid to rest / in the quiet evening / bring me silently / to the seashore).

It is taken from the final version, but with the last two lines exchanged in order to match the abab rhyme scheme of the earlier variant: "Luceferi ce răsar / Din umbră de cetini / O să-mi zâmbească iar / Fiindu-mi prieteni" (Rising evening stars / from the shadow of the branches / will smile on me again / having been my friends).