# If you'd like to omit non-matching lines from the result; add ';d' to the end of the expression.
sed -E 's/(.*?): (.*)/$1 xxx $2/gm;t' <<< "Matthäuspassion, SWV 479: Introitus:Test
Matthäuspassion, SWV 479:Introitus:Test
letztlich
Matthäuspassion, SWV 479: Introitus - Test
Erster Text, zweiter Text : Dritter Text
Vierter Text, fünfter Text : Sechster Text
Siebter Text, achter Text : Neunter Text"
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for SED, please visit: https://www.gnu.org/software/sed/manual/html_node/The-_0022s_0022-Command.html