Mr Kelly's racing tips do not get off to as fast a start as Classic FM appears to have. The letter is one of 'suitcases' of mail received at the station since it came on air in September, praising its round-the-clock service of 'the world's most beautiful music'.
Following initial hiccups, Tony Scotland, a former Radio 3 producer, has tutored Mr Kelly with the pronunciation of some names. Many listeners have noticed an improvement.
'We can't read our letters out,' laments Mr Kelly. 'They are just too generous, telling us we have changed their lives, that the station is on in every room of the house.'
The evidence of the mailbag is borne out next week by the first official audience research on national radio listening habits since Classic FM came on air. Rajar (Radio Joint Audience Research) is the first ever jointly agreed ratings system measuring both commercial radio and BBC stations. The bulk of its findings remain secret but reliable leaks indicate that Classic's recipe of classical 'hits' is winning an audience as high as 10 per cent each week - equivalent to 4.5 million people. Radio 3 can expect only half that figure.
The news is exciting the commercial radio sector, long in the shadow of commercial television and never able to break free of a measly 2 per cent share of all advertising spend.
Sitting opposite Kelly is his producer, Jane Jones, who assists him in his three-hour weekday programme, as he juggles commercials and jingles with reading traffic and weather reports, offering tips for Haydock Park and introducing Brahms and Bach. As Vivaldi fades out, he fades in an advert for Connections, a board game: 'Shall we play the Handel?' he asks his producer. 'No, what about some Schubert?'
Ms Jones misses the questions as she is ushering her three-year-old son into the studio, who has come to see 'what mummy does'.
It was never like this at Radio 3, where the studio is sacrosanct and only the presenter is allowed in. But then Radio 3 never had audiences like this either. If the letters were an early indication that the station was playing the right tunes in many British households, the response to one competition was more evidence. According to the ebullient Michael Bukht, programme controller, in one 15-minute period British Telecom measured 32,000 attempted phone calls from listeners eager to win a boxed set of classical CDs. Calls totalled 135,000 over the week.
Classic's 9-10 per cent audience share means that three months after its launch it can lay claim to being the fourth most popular station in the country - ahead of Radio 3 and Radio 5 (but behind Radios 1, 2 and 4).
Its success comes as no surprise to Nicholas Kenyon, Head of Radio 3, which was widely perceived to be vulnerable to the populist approach of the newcomer. He is undismayed by Classic FM's large audience. The Radio 3 line is that comparisons are futile, like comparing the Daily Mail and the Times just because they both print news.
'Classic FM set out to be popular and it is not playing anything that anyone doesn't like. It has to deliver an audience to advertisers, while we are extending choice by the breadth of our repertory.'
By originating so much of its output, Radio 3, which targets a 'committed classical music following,' is, according to Kenyon, 'investing in the cultural life of the country'.
First indications are that while Radio 3 may have lost some of its listeners to the new station, it has held up better than might have been expected.
Mr Bukht believes that a substantial part of his new audience has come from Radios 1 and 4, followed by listeners to independent local stations. 'Radio 3 has never been my concern. We're a mainline popular music station competing for the big mass-market audiences of Radios 1, 4 and 2.'
Mr Kenyon claims that Classic's success will ultimately play into his hands: 'What will those listeners do when they want more than bite-sized chunks of classical music? If they want to be challenged a little more they will tune to Radio 3.'
If, as expected, the figures show that Classic FM has attracted listeners from independent local stations, how serious a problem does ILR face? Brian West, at the Association of Independent Radio Contractors, believes the expected audience loss is a blip caused by the change in measurement systems. Independent local radio is putting on a brave face by comparing the change to the lower share recorded for ITV companies when the television research system changed.
Whatever the truth, warning bells will ring among ILR contractors if independent national radio (INR) stations such as Classic FM - and, from March, Virgin Rock - are winning audiences primarily at the expense of ILR. The great promise of INR has been that it will accelerate the decline in share of BBC services, forcing advertisers to take radio as a medium more seriously.
Ralph Bernard, chief executive of GWR (which owns five independent local radio stations) and now on the board of Classic FM, believes INR will join with ILR to transform the performance of radio as an advertising medium. He says GWR's own tracking indicates no particular change in its audiences during Rajar's first period.
There is evidence that Classic FM is already persuading ad agencies to take radio more seriously. Collett Dickenson Pearce (CDP) was 'forced' to consider Classic FM for its client Hamlet cigars when the law changed and prevented it using television. According to Simon North, an account manager at CDP, a two-week 'Hamlet Moment' campaign on Classic FM generated a 'frighteningly high response - six times what we anticipated'.
And if critics used to the measured, sober presentation of classical music on Radio 3 were uncomfortable with Lancias and ice-cream being mixed up with their precious composers, Mr Bukht claims listeners have no such inhibitions.
Guy Lamming, media analyst at James Capel, is similarly enthusiastic about the station's first showing: 'It is vital that the first national radio station funded by advertising does succeed. It needs pounds 7m in advertising revenue in its first year and it looks as though it will pass that easily and become a significant profit-generator.'
He is optimistic that the radio sector will break its current 2 per cent share of advertising, and has high hopes both for Atlantic 252, the Dublin-based rock station, which appears on the research findings for the first time next week, and for Virgin Rock.
'The industry has been waiting for a commercially minded national station,' says CDP's Simon North. 'Classic FM seems to have its foot in the door.'