What is the name of the Shabbat before Tisha b'Av?
The Shabbat is called "Shabbat Chazon." The Haftarah of this Shabbat begins with the words "Chazon Yeshayahu," "the vision (prophecy) of Isaiah" concerning the destruction of the Holy Temple.
Rabbi Levi Yitzchak of Berdichev (an eighteenth century chassidic master) explained the deeper meaning behind this Shabbat's name: On this Shabbat every Jew is shown a "vision" of the Third Holy Temple. The purpose of this vision is to arouse within every Jew a yearning to see this G-d-built edifice, and to do as many mitzvahs as possible in order to realize this ambition. While this vision may not be sensed by the physical eyes, certainly the soul experiences this vision, which affects the person on the sub-conscious level.
In most congregations, the tune of the Haftarah is the same as the entire year. There are those who have the custom of reading the Haftarah in a sad, broken tone.