Q. Is it correct to sing on Friday night - Shabbos Chazon the niggun of Lecha Dodi using the sad tune of E-li Tzion that we sing after Kinos on Tisha Beav? Is that not "Avelus Befarhesia" or a case of open mourning that is prohibited on Shabbos?
A. Horav Shlomo Miller’s Shlit’a opinion is that as a mater of fact we have several similar traditions, such as the very sad maftir itself of that Shabbos or the reading with the tune of Eicha of a posuk on the parsha of that Shabbos.
It is all correct to do so, due to the seriousness and closeness of that Shabbos to Tisha Beav.
Rabbi A. Bartfeld as advised by Horav Shlomo Miller and Horav Aharon Miller Shlit’a