Aldridge, Maisie: The Bass Clef Book
Ideally, a piano pupil should learn the treble and bass clefs simultaneously, absorbing both without difficulty. There is, however, an increasing number of children and adults, including students at training colleges, who begin piano lessons with a working knowledge of the treble clef but who are entirely ignorant of the bass.
Many have gained their knowledge of the treble, but not the bass clef, in good singing and aural training classes at school; others, and there are many of them, play the recorder, whilst violinists and players of various wind instruments are in the same position when they learn the piano for the first time.
It frequently happens, too, that piano pupils, and not only young children, are prompted by musical curiosity to read enthusiastically anything written in the treble clef fluently, but the bass clef lags far behind.
For all those people mentioned above, it is an urgent matter to learn the bass clef thoroughly and quickly, in as musical and interesting way as possible, and it is for them that this book is intended. A spell of concentrated work upon the bass clef alone can work wonders.