Bill Callahan, also known as Smog and (Smog), is an American singer-songwriter. Callahan began working in the lo-fi genre of underground rock, with home-made tape-albums recorded on four track tape recorders. Later he began releasing albums with the label Drag City, to which he remains signed today.
In July of 2010 Drag City published Callhan's Letters to Emma Bowlcut, which is an epistolary novel told through a series of letters.