The charts we use from November 1952 onwards are taken from the Official Charts Company which produces the UK Singles Chart for the music industry, including the BBC. The Official Charts Company is a joint venture between the British Phonographic Industry (BPI) and the Entertainment Retailers Association (ERA).

The official UK pop charts based on record sales did not start until 14th November 1952, by which time recorded discs had become widely available in the United Kingdom. For earlier dates than this, we have used the weekly pop chart based on the sales of sheet music, which outsold records until the early 1950s.

The sheet music charts were published from 29th May 1947 by the Wholesale Music Distributors Association, and then the Music Publishers Association. It appeared in the weekly music newspapers New Musical Express and Melody Maker and was broadcast by Radio Luxembourg on Sunday nights. (They did compile a weekly chart of best selling sheet music before May 1947, but this was in alphabetical order rather than sales volume!)

The most popular songs in the 1940s and 1950s were often recorded by several different artists but sheet music was credited to the writers of the song not the performer. For the sake of consistency with the later charts, we have included the name of the artist who we consider to have been most strongly linked with each song in the UK. Where it was difficult to pick out a single artist, we used the Billboard charts from the USA as a guide since these did use record sales and radio plays as well as sheet music sales.

The date shown for each week's Number One on our website is the first day of the week in which the record was top of the charts. This is the record that we use for someone born on this date shown, or any of the six days following this date. It reflects sales of the record (or sheet music, prior to 1952) made in the previous week.

The UK Singles Chart changes every Friday when a new Number One song is announced, but this has not always been the case since the charts began:

Please be aware that there is some confusion about which days of the week the charts began and ended at different times in their history since 1952. Here is an example:

The Guinness/Virgin Book(s) of British Hit Singles state that Do They Know It's Christmas? by Band Aid was Number One for the week commencing Saturday 15 December 1984.

However, the list of Number Ones published by the Official Charts Company states that Do They Know It's Christmas? was Number One for the week ending Saturday 15 December 1984. We support this approach because:

• The song was recorded on 25 November and started to be sent out to record shops a few days later from 29 November onwards.


• The first Singles Chart featuring the Band Aid record was compiled on Sunday 9 December and announced on BBC Radio 1 on Tuesday 11 December. Band Aid went straight into this new chart at Number One.


• The new chart was announced to millions of viewers on BBC1 Top of the Pops on Thursday 13 December with this song by Band Aid played as the week's new Number One record. (You can see a YouTube video clip of the chart rundown here.)

So it makes sense that if one was born between 9-15 December, one would think that the Number One record on any day of this week was by Band Aid. So our website shows that the record was Number One in the week starting 9 December and ending 15 December, as does the Official Charts Company chart for this week but not the Virgin/Guinness reference books.

The only small quibble we have with this approach is that during much of the 1970s and 1980s, there was a full chart show on BBC Radio 1 on Sunday evenings which played all of the songs in the chart from the week before.

In the example above, the Radio 1 Chart Show would have first played Band Aid as the Number One record on Sunday 16 December, whereas the Official Charts Company method has the following week's chart starting on this same Sunday.

The final Sunday chart rundown show on which Radio 1 played Band Aid as the Number One record was broadcast on 13th January 1985. You will see that we and the Official Charts Company show that I Want to Know What Love Is by Foreigner was Number One starting on this date.

We have followed the approach and data provided by the Official Charts Company in spite of this quibble.

From October 1987, the Radio 1 chart show on a Sunday changed and announced the new chart for the following week instead, as it did until July 2015 when the method changed and the new chart was announced on a Friday instead.

We now use the data provided by the Official Charts Company in their archive of weekly chart listings from November 1952 which can be found here: http://www.officialcharts.com/charts/singles-chart/19521114/7501/

Please note that the Official Charts Company also features a list of Number Ones by week since 1952. You can find this list of Number Ones here: http://www.officialcharts.com/chart-news/all-the-number-1-singles__7931/. However we believe this is inconsistent with the weekly chart listings on their own website. The dates shown in this list of Number One records are the week starting dates from 1952 up to 3 August 1969. Subsequent dates are week ending dates.

This list is also different to that used by the popular reference books such as The Guinness Book of British Hit Singles (now The Virgin Book of British Hit Singles) and others. This guide has been a bible to many since it was first published in 1977 and features the list of all Number One singles with the "date on which the disc hit the top" (1979 edition) or more ambiguously "the date of the first week at No.1" (2011 edition).

These books were the authority on chart data for many years and so we used this data until January 2017 when we changed to the data provided by the Official Charts Company in their archive of weekly chart listings.

We support this change because it is the method used for detailed chart data by the research organisation recognised by the entire UK music industry, and because it makes practical sense as we hope we have shown using the Band Aid example above.

Working out what was Number One on someone's birthday ought to be simple. But it depends where you look for the data, and we are very concerned that we get this right.

No customer has challenged us on this until now, but If do you give one of our framed records as a gift and find that the recipient disagrees with the choice of Number One record on their day of birth, citing The Guinness/Virgin Book of British Hit Singles, then please do contact us. We do accept there is room for confusion and we will replace the framed record free of charge should this happen to you.

The first national UK pop charts based on record sales began on 14th November 1952. However a weekly pop chart was published for a few years before this based on the sales of sheet music, which outsold records in the United Kingdom until the early 1950s. This chart was published by Melody Maker and broadcast by Radio Luxembourg from 29th May 1947. The "chart week" began on the day Melody Maker was published.

Between 1952 and 1960, music historians at the Official Charts Company and The Guinness/Virgin Book of British Hit Singles etc. use the chart that was published every Friday in the New Musical Express (now known as NME) from November 1952.

Between 1960 and 1969, music historians use the chart published in Record Retailer/Music Week, although the BBC at the time used a combined chart drawn from separate charts published in the NME, Melody Maker, Disc and Record Mirror to compile the charts used on Pick of the Pops and Top of the Pops on BBC radio and television.

The first true industry-recognised singles chart - referred to as the UK's "official" chart - was introduced in 1969 when the BBC and industry magazine, Record Retailer (later renamed Music Week) joined forces and commissioned the British Market Research Bureau (BMRB) to compile the UK's charts on their behalf.

Prior to 2001, the Official Charts Company was known as the Music Information Chart Service, set up by the industry magazine, Music Week, in co-operation with the BBC, the BPI and retailers association BARD (now the ERA).

You can read a much more detailed history of the official charts at the Official Charts Company website here: http://www.officialcharts.com/who-we-are/history-of-the-official-charts/