From the website for Odense Aafart   , a commercial passenger boat operation on the Odense River.



Sejle op ad åen

(Sail up the river, literally, though we would probably say, Sailing up the river, no? This has become a set phrase in Danish.)

"The song was written about the Odense river (Odense å). It originally had several verses which were different from the words we sing today.
Lyrics written by Laurits Stephan and melody composed by Emilius Carl Wilhelmi.
The song was apparently first performed for the first time on July 12 or 13 1895 at Odense Sommertheater by the tenor Edvard Agerholm.
In 1934 Crown Prince Frederik (later king Frederik IX) conducted the royal guard's orchestra at the guard's rehearsal room in Rigensgade (Rigens Street) in Copenhagen. One of the musicians was playing with the melody of "Sejle op ad åen". When the Crown Prince heard him, he said to the head of the orchestra: "What a wonderful melody, we often sing it when we're out sailing. I think you should play it at the football pitch.". They did this and with great success, one must say.
In the beginning of 1981 there was an interview with Queen Margrethe on TV, where she related her impressions of Japan. She was asked, among other things, if Danes could learn to understand the Japanese mind set. She replied that they could, but they would never "sail up the river together".
"Sailing up the river together" has become a concept implying more than common understanding of one another. When you sail up the river together with someone, you imply a deeper friendship, combined with festivities and good cheer.
We all know that wherever Danes congregate, be it at the local hall, at a football match or in the vacations paradises of southern Europe, you'll often hear them break out in cheerfall singing, with the words:

Sejle op ad åen…

The song goes on for as long as strength and stamina allow, it doesn't take much memory. The singers often link arms, rocking back and forth to symbolize "sailing on the river" and strengthen the feeling of comradeship.

All of Denmark knows this popular song and people in Odense feel that they are always singing about their city. But then, they're use to "sailing on the river".

We sail on the river every summer from May 1 to September 30."

Bassen again: You're right about the typos. They're the same verse, but mashed up with typos. The same verse is sung over and over again. A drinking song, a football song, a song for happy Danes…
As literally as possible the lyrics mean:


Sejle op ad åen = sailing up the river
Sejle ned igen = sailng down again
Det er vel nok en dejlig sang = that is such a lovely song
Den må vi ha' endnu en gang = We must have it one more time.

And so on and so on.
Good luck!

Bassen