If La Espero is the movement's hymn, this is its marching song. Antoni Grabowski - the chemist who made the first Esperanto translations of Pushkin and Mickiewicz - published it in 1913, and through the 1920s it was sung at congresses right after the anthem. When the first Esperanto music records came out in 1926, La Tagiĝo was one of the three titles.
The image doing the work is o - daybreak - and it is also the
word-building lesson: tago (day) plus -iĝ- (becoming) plus -o.
Day-becoming. You built forty affixes in this course; here is one
carrying a whole song. Listen for too - the shadows of
night do not merely run, they run away, for- doing exactly what the
affix track taught.
One textual footnote: our 1913 source has - the starry banner - where later songbooks often print la verda standardo, the green one. Both circulate; we print what Grabowski published.
Every clipped word here - fratar', mar', mond' - is Rule 16 elision doing the metre's bidding; poetic Esperanto explains the rules the apostrophe has to obey.