With no explanation, label each line with "O", "person-artist/author", "person-actor", "art-other", "art-broadcastprogram", "art-film", "art-music", "art-painting", "art-writtenart" or "building-airport" preceded by ":".
Their
debut
opera
,
``
The
Lion-Faced
Man
``
,
appeared
at
in
August
2015
,
including
a
libretto
by
Hel
Gurney
and
sung
by
Alison
Wells
.
Their:O
debut:O
opera:O
,:O
``:O
The:art-other
Lion-Faced:art-other
Man:art-other
``:O
,:O
appeared:O
at:O
in:O
August:O
2015:O
,:O
including:O
a:O
libretto:O
by:O
Hel:person-artist/author
Gurney:person-artist/author
and:O
sung:O
by:O
Alison:person-actor
Wells:person-actor
.:O