Depicted person:  <a href="https://www.wikidata.org/wiki/Q1691941" class="extiw" title="d:Q1691941"><span title="Norwegian composer, conductor and musicologist (1820-1890)">Johan Didrik Behrens</span></a> – Norwegian composer, conductor and musicologist (1820-1890)
<bdi><a href="https://www.wikidata.org/wiki/Q18560026" class="extiw" title="d:Q18560026"><span title="Danish photographer">Johannes Petter Lindegaard</span></a>
</bdi>
CC BY-SA 4.0
Oslo Museum: image no. <a rel="nofollow" class="external text" href="http://www.digitaltmuseum.no/things/011014342111/OMU/OB.F03818b">OB.F03818b</a>, via digitaltmuseum.no.