The level of sales made by a record shop can be greatly affected by the time of year. Christmas is the busiest time of the year for the majority of record shops - on average around half of the year's takings are taken in this period with December being the busiest month of the Christmas quarter - although this is now rivalled by the Record Store Day promotion in April in participating shops. So it's important that you make an allowance in your cash flow estimates for the increased amount of stock that you will need to buy for these periods as well as the increased sales. You may also need extra staff in this period, in which case the wages payments should also be adjusted upwards.
Television programmes such as the X Factor and The Voice can have a huge impact on music sales and on dictating popular music tastes which may or may not affect your business, depending on the type of music that you stock.