Define a command like \bfseries

I want to define a command that applies to all text within the current scope, like \bfseries. I need this, because the leadsheets package allows me to pass a label-format command to an environment, which will then be inserted at the start of the label (in my case the numbering in front of a verse). I'd like to draw a circle around the number. For this, I found this code

\usepackage{tikz}
\newcommand*\circled[1]{\tikz[baseline=(char.base)]{
\node[shape=circle,draw,inner sep=2pt] (char) {#1};}}


which works great when I'm able to directly wrap it around the text I want to circle. The problem is now, that if I just pass label-format=\circled tex complains that a } is missing and if I use label-format=\circled{} the compiler is fine, but obviously nothing happens.

How can I achieve the effect described above? label-format=\bfseries works perfectly, so I need a command that automatically wraps around the following text.

Unfortunately, I don't know how you call such commands in LaTeX so I couldn't search for it.

• That's not possible, \circled cannot be written font switch command. Hacking the leadsheets package seems the better approach. But the package is not on CTAN. A MWE and a link to the package would be useful. – Heiko Oberdiek Jul 18 '18 at 17:30
• I expected that it would be hard/impossible. Too bad :/ By the way: The package can be found on ctan: ctan.org/pkg/leadsheets?lang=en – Taxel Jul 18 '18 at 17:32
• I had searched for leedsheets instead of leadsheets. – Heiko Oberdiek Jul 18 '18 at 17:59
• This requires a small change in \leadsheets_verse_label:n I think. Probably worth a feature request... – clemens Jul 18 '18 at 19:08
• An MWE would give you a better chance of an answer. – cfr Jul 19 '18 at 2:12

Starting with v0.6 (2019/10/02) leadsheets allows that the last formatting command of verse labels may accept a mandatory argument:

\documentclass{article}
\usepackage{tikz}
\newcommand*\circled[1]{%
\tikz[baseline=(char.base)]{
\node[shape=circle,draw,inner sep=2pt] (char) {#1};
}%
}

verse/numbered,
verse/label-format = \circled
}

\begin{document}

\begin{song}{title=My Song}
\begin{verse}
bla bla
\end{verse}
\begin{verse}
blub blub
\end{verse}
\end{song}

\end{document}