English-language summary of Dillmar's dissertation at http://www.haeffner.se/JCFH/DillmarAvh2.pdf.
Discussion of Dillner, psalmodikon:
To improve the singing of the congregations the dean Johan Dillner did some pioneer work that later had several imitators who together secured the future of the chorale book. The problem was the general public whose insufficient ability to read music was solved by a musical notation using numerals in combination with a easily played instrument for the practise of the melodies. Dillner’s method was presented by Wallin in the Riksdag with support of several acknowledged  musicians, among others Hæffner. The KMA desired that all parishes in the Kingdom should be requested to use this method, since all were in need of improvement in chorale singing.
In his numerical chorale book Psalmodikon Dillner in 1830 presented not only the melodies in an easily comprehensible way, but also informed the readers of his theomusicological ideas. Here was a strong Moravian influence, even though Dillner in some respects also showed criticism towards this singing tradition. Considering the wide distribution of his edition the significance of this theomusicology should not be underestimated. Emphasized was the strong communicative ability of chorale music, founded on symbolism and style of music, thus both cognitive and psychological. However, for its effectiveness a carefully prepared pedagogy was needed. Though Dillner placed the old modal melodies in a unique position, he did not hesitate to recognize instrumental music and major/minor tonality as also being of value. The four-part singing of chorales was described as a musical religious exercise. However, his purpose was not to replace the unison singing of the congregation with a four-part choir, but to improve its purity and euphony. As a choirmaster Dillner encouraged singing in his parishes and the audible results surprised not only his neighbourhood but also the KMA.