TISM (an acronym of This Is Serious Mum) was an Australian alternative rock band from Melbourne. The band was formed in 1982 and broke up in 2004. The true identities of the members of TISM have been kept secret. For this reason, the band often appear in balaclavas when they play concerts, although they have also been known to indulge in ridiculously complex costumery to the same end. They have been thought to have been influenced by The Residents in this regard. However, the true identities of the members are common knowledge among fans of the band.