New bib(la)tex-entrytype for music-scores

Question

Short question: How can I create a new entry type (@music) with fields for the composer, title, opus, editor, series, location and year?

\begin{filecontents*}{\jobname.bib}
@music{citekey,
    composer={Johann Sebastian Bach},
    title={Motetten},
    number={BWV 225--230},
%   opus={}, % no opus in this case
    editor={Konrad Ameln},
    series={Neue Bach-Ausgabe Serie III, Band 1},
    loaction={Kassel},
    publisher={Bärenreiter},
    year={1965},
}
\end{filecontents*}

\documentclass[ngerman]{scrartcl}
\usepackage[style=authortitle]{biblatex}
\bibliography{\jobname}

\begin{document}
\cite{citekey} should look like

Johann Sebastian Bach: Motetten. BWV 225-230, hrsg von Konrad Ameln
= Neue Bach-Ausgabe Serie III, band 1. Kassel: Bärenreiter, 1965

or in general

(composer): (title)[, (opus)][, (number)][hrsg. von (editor)][= (series)].
[(location)][: (publisher)][, (year)][.]

where (xxx)=field and [yyy]=optional

\printbibliography
\end{document}

Answer 1

\documentclass[ngerman]{scrartcl}
\usepackage[ngerman]{babel}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[style=authortitle,backend=biber]{biblatex}
\DeclareBibliographyDriver{music}{%
  \usebibmacro{bibindex}%
  \usebibmacro{begentry}%
  \printfield{usera}%
  \setunit{\labelnamepunct}\newblock
  \usebibmacro{maintitle+title}%
  \newunit
  \printfield{userb}%
  \newunit\newblock
  \printfield{number}%
  \newunit
  \usebibmacro{byeditor+others}%
  \setunit{=\addspace}
  \printfield{series}%
  \setunit{\adddot\addspace}
  \usebibmacro{publisher+location+date}%
  \newunit\newblock
  \usebibmacro{finentry}}

\renewcommand{\labelnamepunct}{\addcolon\space}
\renewcommand*{\newunitpunct}{\addcomma\space}
\DeclareFieldFormat{title}{#1}

\bibliography{9}
\begin{document}
\cite{citekey} should look like

Johann Sebastian Bach: Motetten. BWV 225-230, hrsg von Konrad Ameln
= Neue Bach-Ausgabe Serie III, band 1. Kassel: Bärenreiter, 1965

or in general

(composer): (title)[, (opus)][, (number)][hrsg. von (editor)][= (series)].
[(location)][: (publisher)][, (year)][.]

where (xxx)=field and [yyy]=optional

\printbibliography
\end{document}

And the corresponding .bib file:

@music{citekey,
    usera={Johann Sebastian Bach},
    userb={myopus},
    title={Motetten},
    number={BWV 225--230},
    editor={Konrad Ameln},
    series={Neue Bach-Ausgabe Serie III, Band 1},
    location={Kassel},
    publisher={Bärenreiter},
    year={1965},
}

Answer 2

My answer builds heavily on Thorsten's answer. I added the following modifications:

• Instead of using a custom field for the composer, I made use of the author field and the bibmacros built upon on it. Otherwise (as in Thorsten's example), bibliography entries will be listed under the composer in the bibliography, but in-text citations will show the editor's name instead (which I suppose is not what one wants).

• The format of the custom field used for the opus should default to "op.~" plus the field's content (so there's no need to type "op.~" every time). I have customized the format so that it will use the contents of the field userc as prefix if this field is defined (e.g. as "BWV").

• I have added support for back-referencing. These references may be turned off by removing the respective package option.

The content of the series field should probably be split up into separate fields, but I have left it alone for now.

\documentclass{scrartcl}

\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[ngerman]{babel}

\usepackage[style=authortitle,backref=true]{biblatex}

\DeclareBibliographyDriver{music}{%
  \usebibmacro{bibindex}%
  \usebibmacro{begentry}%
%   \printfield{usera}% DELETED
  \usebibmacro{author/editor+others/translator+others}% NEW
  \setunit{\labelnamepunct}\newblock
  \usebibmacro{maintitle+title}%
  \newunit
  \printfield{userb}%
%   \newunit\newblock% DELETED
  \newunit% NEW
  \printfield{number}%
%   \newunit% DELETED
  \newunit\newblock% NEW
  \usebibmacro{byeditor+others}%
  \setunit{=\addspace}
  \printfield{series}%
%   \setunit{\adddot\addspace}% DELETED
  \setunit{\addperiod\space}% NEW
  \usebibmacro{publisher+location+date}%
%   \newunit\newblock% DELETED
  \setunit{\bibpagerefpunct}\newblock% NEW
  \usebibmacro{pageref}% NEW
  \usebibmacro{finentry}%
}

\renewcommand*{\labelnamepunct}{\addcolon\space}
\renewcommand*{\newunitpunct}{\addcomma\space}
% \DeclareFieldFormat{title}{#1}% DELETED
\DeclareNameAlias{sortname}{first-last}% NEW
\DeclareFieldFormat{userb}{% NEW
  \iffieldundef{userc}{%
    op.~#1%
  }{%
    \printfield{userc}~#1%
  }%
}
\DeclareFieldFormat{number}{\bibstring{number}~#1}% NEW

\usepackage{filecontents}

\begin{filecontents}{\jobname.bib}
@music{citekey,
  author = {Johann Sebastian Bach},
  title = {Motetten},
  userb = {225--230},
  userc = {BWV},
  editor = {Konrad Ameln},
  series = {Neue Bach-Ausgabe Serie III, Band 1},
  volume = {1},
  location = {Kassel},
  publisher = {Bärenreiter},
  year = {1965},
}
\end{filecontents}

\addbibresource{\jobname.bib}

\begin{document}

Ein wenig Text \autocite{citekey}.

\printbibliography

\end{document}