Some composers were known by more than one name. Others have names with prefixes, for example “de Lassus”, and sometimes the prefix is missing in scores. If you enter a name and then tap “Refresh List” but don’t find the composer, turn on the “AKA” option switch to add the contents of the AKA field to the name search. Then try again.
You don’t need to enter letters with diacritical marks such as ü. Just enter the letter without the diacritical mark for a search by name. For example, to search for Heinrich Schütz, enter “Schutz” for the last name.