Q: Could you describe what a 13/8 time signature is?
A: sure. that means there's 13 eighth-notes per a bar. where in a normal time signature there would likely be just 8 eighth-notes. Indeed if we're counting we also notice there would be 6 and a half 'quarter-notes' per bar of 13/8, whereas in a normal time signature there'd typically be just 4. also it should be noted that depending where you live, a "bar" might be called a "measure", and an "eighth-note" might be called a "quaver", and a "quarter-note" might be called a "crotchet". and a time-signature indeed might be called a "meter"