The dialect of old german sounds nearer to Scandinavian

Scandinavian culture ended 1000 years ago. Old High German would have sounded more nordic as it was naturally very closer to proto-germanic than modern german. But here is the important part to remember, is that the High German consonant shift in the 8-11th century varied to various degrees among dialects. In other words, dialects that were spoken closer to the border of Saxony would have had less amount of the consonants shifts than the dialects farther south. So, for example, the “th” sound was still retained among northern onces to a far greater degree than in the south, where the “th” had long been transformed into a “D” (ethel (noble) vs edel). Same goes for other letter transformations such as D –> T (God vs Gott, Cald (Cold) vs Calt, Diep (Deep) vs Tief, doan (to do) vs tun), or T –> S/Z (better vs besser, bittan (to bite) vs bizzan), or F/V –> B (Gifan (to give) vs Geban), K -> H (maken (to make) vs mahon). So some dialects of Old High German would have had more of these transformations, hence they would sound LESS nordic, while the northern ones closer to the Low German-speaking areas would sound nore nordic as a result of having less amount of consonant transformations. The High German Consonant Shift happened in the 7th to 8th c.. South German runes of the 6th c. don’t show any sign of that shift. Example (Neudingen-Baar): blithguth uraitruna = blithguth wrait runa = blithguth scribed the runes = blithguth wrote the runes (Blithguth > mod. German: Bliedgund, because th > d). 6th c. West Germanic wrait > 8th c. Old High German rizzen, t > zz (mod. German ritzen, zz=tz).

The Germans are composed of 5 different tribes, only one of which is that of the Franks. The Salian Franks came from the area of the Low Countries, while the Ripuarian Franks came from the region along the Rhine. Scandinavians migrated to Scandinavia from Germania. They are Germanic tribes. So actually Scandinavian sounds like old German.

At the end of the Western Roman Empire and the post-Roman period that followed, many of the Franks (though of course not all) went south. In the early Middle Ages, they founded a number of smaller kingdoms in what is today Belgium and France, but not in Germany. Eventually those kingdoms were united and they grew in size, becoming an Empire under Charlemagne.

If you look at a map depicting that era, you will see that the mejority of the Frankish territory is inside the realm that the Romans called Galia, that is France.

There was no separate German Frankish state at the time, and that is the reason why in the German language, Germany is called Deutschland but France is called Frankreich.

Evidently, not all French were/are Frankish, just like not all Germans were/are Saxon or Swabians, but the essence of Frankish institutions and culture reached its zenith in France, with Frenchmen, not Germans. And even while later the Empire that became known as the Holy Roman Empire had at its head a powerfull ruler based in Germany, he was not known as Emperor or king of the Franks.

The Frankish empire covered a lot of ground multiple language zones. In late Roman times the Franks had divided into two groups, the Salian Franks on the North Sea coast and the Ripuarian Franks in the Rhineland. The Ripuarian area evolved into a duchy called Franconia and the local dialect was influenced by the High German sound shift. This Franconian dialect of Old High German is what we are hearing. Farther north the sound shift never reached the Salian Franks. Their dialect eventually evolved into Old Dutch, but back in Charlemagne’s time it was still pretty similar to Old Low German (spoken by the Saxons) and Anglo-Saxon (Old English). Since Charlemagne was born near Liege in modern Belgium he probably spoke the Low German dialect. He had close relations with the English and could probably understand their speech without much difficulty.

Only the king of France was known as Rex Francorum during the Middle Ages
As for the language of Charlemagne, he spoke Frankish, not German.Both French and Getman were still not well developed as languages during that time.Much like the early Saxon kings in the English Heptarchy, who spoke Saxon or Angle, but not yet English.

Norman adopted the Latin language,  the language of those who made us forget our pagan spirit

Example of Old High German lyrics

Verse: 1 Thes hábet er ubar wóroltring \ giméinit einaz dágathing,
Verse: 2 thíng filu hébigaz, \ zi sorganne éigun wir bi thaz.
Verse: 3 Thir zéllu ih híar ubarlút: \ nist nihéinig siner drút,
Verse: 4 thes álleswio bigínne \ ni er quéme zi themo thínge.
Verse: 5 Quément thara ouh thánne \ thie wénegun álle
Verse: 6 thie híar gidatun fóllon \ then iro múatwillon.
Verse: 7 Zi zéllenne ist iz suári! \ nist ther fon wíbe quami
Verse: 8 (es irquímit muat mín), \ nub er thár sculi sin;
Verse: 9 Ni síe sculin hérton \ thar iro dáti renton
Verse: 10 al io giwísso umbiríng, \ theist filu jámarlichaz thíng!
Verse: 11 Ward wóla in then thíngon \ thie selbun ménnisgon,
Verse: 12 thie thar thoh bígonoto \ sint síchor iro dáto;
Verse: 13 In thie thoh úbil thanne \ nist wiht zi zéllenne,
Verse: 14 mit thíu sih thoh biwérien \ joh étheswio ginérien!
Verse: 15 Wanta es nist lába furdir, \ thaz gilóubi thu mir,
Verse: 16 er wérgin megi ingángan \ (wérd er thar bifángan),
Verse: 17 Nub er scúli thuruh nót \ (wérd er thar birédinot)
Verse: 18 thúlten thanne in éwon \ thes hélliwizes wéwon.
Verse: 19 Ward wóla in then thíngon \ thie selbun ménnisgon,
Verse: 20 thie thar thoh bígonoto \ sint síchor iro dáto!
Verse: 21 Weist thu wío bi thia zít \ ther gotes fórasago quít?
Verse: 22 er zélit bi thaz selba thíng, \ thaz thar si míhilaz githuíng;
Verse: 23 In ímo man thar lésan mag \ theiz ist ábulges dag,
Verse: 24 árabeito, quísti, \ joh managoro ángusti;
Verse: 25 Thaz íst ouh dag hórnes \ joh éngilliches gálmes,
Verse: 26 thie blásent hiar in lánte, \ thaz worolt úfstante;
Verse: 27 Theist dag ouh níbulnisses \ joh wíntesbruti, léwes!
Verse: 28 thiu zuei firwázent thanne \ thie súntigon alle;
Verse: 29 Hérmido ginóto \ joh wénagheiti thráto
Verse: 30 (waz mag ih zéllen thir hiar mér?) — \ thes ist ther dág al foller!
Verse: 31 Lási thu io thia rédina, \ wio drúhtin threwit thánana?
Verse: 32 thar dúat er zi gihúgte, \ er thanne hímil scutte.
Verse: 33 Wér ist manno in lánte \ ther thánne witharstánte,
Verse: 34 thanne er iz zi thíu gifiarit \ thaz sih ther hímil ruarit;
Verse: 35 Thánne er mit giwélti \ ist inan fáltonti
Verse: 36 (queman mág uns thaz in múat!), \ so man sinan lívol duat.
Verse: 37 Níst ther dag sumiríh \ dagon ánderen gilih,
Verse: 38 thaz sar man in githánkon \ thar mégi wiht biwánkon;
Verse: 39 Gibórganero dáto \ ni plígit man hiar nu thráto,
Verse: 40 sih ougit thár ana wánk \ ther selbo lúzilo githank.
Verse: 41 Ward wóla ménnisgon \ in thén selben thíngon,
Verse: 42 thie thar thoh bígonoto \ sint síchor iro dáto;
Verse: 43 In thie thoh úbil thanne \ nist wiht zi zéllenne,
Verse: 44 mit thíu sih thoh biwérien \ joh étheswio ginérien!
Verse: 45 Ni lósent thar in nóti \ góld noh diuro wáti,
Verse: 46 ni hilfit gótowebbi thár \ noh thaz sílabar in war;
Verse: 47 Ni mag thar mánahoubit \ helfan héreren wiht,
Verse: 48 kínd noh quéna in ware, \ sie sorgent íro thare;
Verse: 49 Odo íawiht helphan thánne \ themo fílu richen mánne:
Verse: 50 sie sint al ébanreiti \ in theru selbun árabeiti.
Verse: 51 Giwísso thaz ni híluh thih: \ thar sorget mánnilih bi sih,
Verse: 52 bi sines sélbes sela; \ nist wíht in thanne méra.
Verse: 53 Skálka joh thie ríche \ thie gént thar al gilíche,
Verse: 54 ni si thíe thar bi nóti \ gifórdoront thio gúati.
Verse: 55 Ward wóla in then thíngon \ thie selbun ménnisgon,
Verse: 56 thie thar thoh bígonoto \ sint síchor iro dáto!
Verse: 57 Thar nist míotono wiht \ ouh wéhsales níawiht,
Verse: 58 thaz íaman thes giwíse, \ mit wíhtu sih irlóse;
Verse: 59 Ni wari thu ío so richi \ ubar wóroltrichi,
Verse: 60 thóh thu es thar bigínnes: \ ther scáz ist sines síndes.
Verse: 61 Wanta drúhtin ist so gúat, \ ther thaz úrdeili duat;
Verse: 62 er duat iz sélbo, ih sagen thir éin, \ ander bótono nihein;
Verse: 63 Bi thiu ist wóla in then thíngon \ thie selbun ménnisgon,
Verse: 64 thie thar thoh bígonoto \ sint síchor iro dáto;
Verse: 65 In thie thoh úbil thanne \ nist wiht zi zéllenne,
Verse: 66 mit thíu sih thoh biwérien \ joh étheswio ginérien!

Another Version

Thes hábet er ubar wóroltring, giméinit einaz dágathing,
thíng filu hébigaz, zi sorganne éigun wir bi thaz.
Thir zéllu ih híar ubarlút: Nist nihéinig siner drút,
thes álleswio bigínne, ni er quéme zi themo thínge.

Ward wóla in then thíngon, thie selbun ménnisgon,
thie thar thoh bígonoto, sint síchor iro dáto;
In thie thoh úbil thanne, nist wiht zi zéllenne,
mit thíu sih thoh biwérien, joh étheswio ginérien!

Quément thara ouh thánne, thie wénegun álle,
thie híar gidatun fóllon, then iro múatwillon.
Zi zéllenne ist iz suári! Nist ther fon wíbe quami,
es irquímit muat mín, nub er thár sculi sin;
Ni síe sculin hérton, thar iro dáti renton,
al io giwísso umbiríng, theist filu jámarlichaz thíng!

Ward wóla in then thíngon, thie selbun ménnisgon,
thie thar thoh bígonoto, sint síchor iro dáto;
In thie thoh úbil thanne, nist wiht zi zéllenne,
mit thíu sih thoh biwérien, joh étheswio ginérien!

Wanta es nist lába furdir, thaz gilóubi thu mir,
er wérgin megi ingángan, wérd er thar bifángan,
Nub er scúli thuruh nót, wérd er thar birédinot,
thúlten thanne in éwon, thes hélliwizes wéwon.

Ward wóla in then thíngon, thie selbun ménnisgon,
thie thar thoh bígonoto, sint síchor iro dáto;
In thie thoh úbil thanne, nist wiht zi zéllenne,
mit thíu sih thoh biwérien, joh étheswio ginérien!

Weist thu wío bi thia zít, ther gotes fórasago quít?
Er zélit bi thaz selba thíng, thaz thar si míhilaz githuíng;
In ímo man thar lésan mag, theiz ist ábulges dag,
árabeito, quísti, joh managoro ángusti;
Thaz íst ouh dag hórnes, joh éngilliches gálmes,
thie blásent hiar in lánte, thaz worolt úfstante;

Ward wóla in then thíngon, thie selbun ménnisgon,
thie thar thoh bígonoto, sint síchor iro dáto;
In thie thoh úbil thanne, nist wiht zi zéllenne,
mit thíu sih thoh biwérien, joh étheswio ginérien!

Theist dag ouh níbulnisses, joh wíntesbruti, léwes!
Thiu zuei firwázent thanne, thie súntigon alle;
Hérmido ginóto, joh wénagheiti thráto.
Waz mag ih zéllen thir hiar mér? Thes ist ther dág al foller!

Ward wóla in then thíngon, thie selbun ménnisgon,
thie thar thoh bígonoto, sint síchor iro dáto;
In thie thoh úbil thanne, nist wiht zi zéllenne,
mit thíu sih thoh biwérien, joh étheswio ginérien!

Lási thu io thia rédina, wio drúhtin threwit thánana?
Thar dúat er zi gihúgte, er thanne hímil scutte.
Wér ist manno in lánte, ther thánne witharstánte,
thanne er iz zi thíu gifiarit, thaz sih ther hímil ruarit;
Thánne er mit giwélti, ist inan fáltonti.
Queman mág uns thaz in múat! So man sinan lívol duat!

Ward wóla in then thíngon, thie selbun ménnisgon,
thie thar thoh bígonoto, sint síchor iro dáto;
In thie thoh úbil thanne, nist wiht zi zéllenne,
mit thíu sih thoh biwérien, joh étheswio ginérien!

Níst ther dag sumiríh, dagon ánderen gilih,
thaz sar man in githánkon, thar mégi wiht biwánkon;
Gibórganero dáto, ni plígit man hiar nu thráto,
sih ougit thár ana wánk, ther selbo lúzilo githank.

Ward wóla in then thíngon, thie selbun ménnisgon,
thie thar thoh bígonoto, sint síchor iro dáto;
In thie thoh úbil thanne, nist wiht zi zéllenne,
mit thíu sih thoh biwérien, joh étheswio ginérien!

Ni lósent thar in nóti, góld noh diuro wáti,
ni hilfit gótowebbi thár, noh thaz sílabar in war;
Ni mag thar mánahoubit, helfan héreren wiht,
kínd noh quéna in ware, sie sorgent íro thare;
Odo íawiht helphan thánne, themo fílu richen mánne:
Sie sint al ébanreiti, in theru selbun árabeiti.

Ward wóla in then thíngon, thie selbun ménnisgon,
thie thar thoh bígonoto, sint síchor iro dáto;
In thie thoh úbil thanne, nist wiht zi zéllenne,
mit thíu sih thoh biwérien, joh étheswio ginérien!

Giwísso thaz ni híluh thih: Thar sorget mánnilih bi sih,
bi sines sélbes sela; nist wíht in thanne méra.
Skálka joh thie ríche, thie gént thar al gilíche,
ni si thíe thar bi nóti, gifórdoront thio gúati.

Ward wóla in then thíngon, thie selbun ménnisgon,
thie thar thoh bígonoto, sint síchor iro dáto;
In thie thoh úbil thanne, nist wiht zi zéllenne,
mit thíu sih thoh biwérien, joh étheswio ginérien!

Thar nist míotono wiht, ouh wéhsales níawiht,
thaz íaman thes giwíse, mit wíhtu sih irlóse;
Ni wari thu ío so richi, ubar wóroltrichi,
thóh thu es thar bigínnes: Ther scáz ist sines síndes.
Wanta drúhtin ist so gúat, ther thaz úrdeili duat;
Er duat iz sélbo, ih sagen thir éin, ander bótono nihein;
Bi thiu ist wóla in then thíngon, thie selbun ménnisgon,
thie thar thoh bígonoto, sint síchor iro dáto;
In thie thoh úbil thanne, nist wiht zi zéllenne,
mit thíu sih thoh biwérien, joh étheswio ginérien!