Pearsall's move abroad brought opportunities to develop his interests as a composer. Although it seems likely that he had some instruction, or at least received advice in composition from the Austrian violinist and composer
Joseph Panny, he would still appear to be self-taught when he wrote most of his early attempts. There is little evidence to support a claim made by Hubert Hunt that his early works included the
Duetto buffo di due gatti, published under the pseudonym G. Berthold and often attributed to
Rossini. Though resident abroad, he kept in touch with his home city of Bristol. Pearsall's last visit to Willsbridge in 1836–1837 coincided with the foundation and earliest meetings of the
Bristol Madrigal Society, for which many of the madrigals and part songs he wrote in the period 1836–1841 were composed. The success of his earliest works for the society encouraged him to write others, including "The Hardy Norseman" and "Sir Patrick Spens" (in ten parts), and eight-part settings of "Great God of Love" and "
Lay a garland". The carol was originally written as a mixture of Latin and German text, and Pearsall, a scholar of German literature, replaced the German sections with English words to rhyme with the Latin phrases. His original text phrasing reflected the pronunciation of
English Vernacular Latin prevalent at the time — thus Pearsall rhymed "O Jesu parvule" with "My Heart is sore for Thee" – but in later versions these phrases have been replaced by "I yearn for Thee alway", reflecting a shift in pronunciation to a more Italianate style of Latin speech. Pearsall's arrangement of "In dulci jubilo" was included by Sir David Willcocks and Reginald Jacques in their popular 1961 music-score collection
Carols for Choirs. Pearsall was an amateur composer. Many of his compositions were not published until after his death, and even now, many remain in manuscript. The particle
de before his name was propagated by his daughter Philippa. Pearsall was the author of several articles and letters that contributed to scholarly understanding of early music in the Roman Catholic and Anglican traditions and helped to re-establish plainsong, Renaissance polyphony, and ancient church hymns in German and English-speaking countries. His antiquarian interests, including history,
heraldry and
genealogy, his rejection of industrialisation, and his search for clarity in musical composition were derived from earlier models and place him firmly in the Romantic movement. He also composed poetry, some of which he used for his madrigals, such as "Why Do the Roses" (1842). In the 1830s, he made accomplished verse translations into English of
Schiller's play
William Tell in 1829 and
Goethe's
Faust. ==Present appreciation==