[1] It was apparently intended to be used for the shepherd’s pipe solo in Act III of Wagner's Tristan und Isolde.
[1] It was used beginning in 1891 at the Festspielhaus, Bayreuth as a substitute for Wagner's Holztrompete; the clarina was found more practical and more effective in producing the desired tone-colour.
[2] The heckel-clarina is a single reed, conical bore instrument made of metal, resembling a soprano saxophone.
According to Heckel's promotional materials, the heckel-clarina's tone resembled that of a cor anglais in its low register, a saxophone in the middle, and a clarinet in its upper range.
[2] The instrument is not to be confused with the heckelphone-clarinet, also a very rare conical bore single reed woodwind by Heckel but lower in pitch and made of wood.