/usr/include/ableton/link/ is in ableton-link-dev 1.0.0+dfsg-2.
This file is owned by root:root, with mode 0o755.
..
/usr/include/ableton/link/Beats.hpp
/usr/include/ableton/link/ClientSessionTimelines.hpp
/usr/include/ableton/link/Controller.hpp
/usr/include/ableton/link/Gateway.hpp
/usr/include/ableton/link/GhostXForm.hpp
/usr/include/ableton/link/HostTimeFilter.hpp
/usr/include/ableton/link/Kalman.hpp
/usr/include/ableton/link/LinearRegression.hpp
/usr/include/ableton/link/Measurement.hpp
/usr/include/ableton/link/MeasurementEndpointV4.hpp
/usr/include/ableton/link/MeasurementService.hpp
/usr/include/ableton/link/NodeId.hpp
/usr/include/ableton/link/NodeState.hpp
/usr/include/ableton/link/PayloadEntries.hpp
/usr/include/ableton/link/PeerState.hpp
/usr/include/ableton/link/Peers.hpp
/usr/include/ableton/link/Phase.hpp
/usr/include/ableton/link/PingResponder.hpp
/usr/include/ableton/link/SessionId.hpp
/usr/include/ableton/link/Sessions.hpp
/usr/include/ableton/link/Tempo.hpp
/usr/include/ableton/link/Timeline.hpp
/usr/include/ableton/link/v1/
/usr/include/ableton/link/v1/Messages.hpp