  Aspects of superstring theory on deformed BTZ black holes, formed near
$k$~NS5 branes by $p$~fundamental strings, and single-trace $T\bar T$
holography, are presented. The excitation energy of a singly wound long string
plus its contribution to the energy of the black hole, $1/p$ fraction of the
black-hole energy, is the same as that in $T\bar T$ deformed $CFT_2$ with
$c=6k$. This supports the claim that the black hole can be thought of as a
state in a symmetric product of $p$~$CFT_2$'s of central charge~$6k$, where the
black-hole energy is split equally among all $p$ factors. A comment on
superstring theory on deformed global $AdS_3$ is also presented.
