“One of my chief pleasures is to hear Till and Don Juan on the wireless, conducted by yourself. What a difference!” So wrote the 91-year-old George Bernard Shaw to the 83-year-old Richard Strauss shortly before Christmas 1947. Shaw was referring to the two concerts broadcast from the Royal Albert Hall that autumn by the BBC Third Programme during the festival of Strauss’s music which the BBC, Sir Thomas Beecham and Strauss’s London publishers had jointly sponsored.

Strauss himself valued the new Third Programme which he had been able to receive in his temporary billet in Switzerland. By a quirk of technology, there was better reception there than there was in London. This anomaly would not have helped Kenneth Leech, the engineer from whose unpublished off-air acetates this rare and important release mainly derives. Were times so hard that neither the BBC nor the Philharmonia’s Walter Legge could afford to make discs of these historic concerts? None appears to exist, though the section featuring the Burleske derives from a technically superior source.

In Till and briefly in Domestica there is audible interference from an adjacent station. Leech also lacked a second machine, which means that, the Burleske apart, brief sections of music are missing every four or five minutes. Not that this matters. Such is the fascination of the musicmaking, the hiatuses are, in Lady Bracknell’s word, “immaterial”.

The transfers of Leech’s flawed acetates are by Testament’s miracle-worker-in-chief Paul Baily. Examples of what the acetates sounded like before treatment are cheekily offered as an addendum to disc 2. The transformation is astonishing. Perhaps Mr Baily should have a go at Strauss’s 1929 Berlin Staatskapelle recording of Don Juan. Until he does, we are bound to conclude that this live Philharmonia performance is not only fierier and more expressive but far better played.

Strauss had a famously economical beat. Even so, for a man of 83 to conduct a concert of this length at this pitch of intensity – after the three principal works he threw in the Rosenkavalier waltzes for good measure – is astonishing. In the opening of Don Juan he yields to no one, not even Toscanini, in the brilliance of his attack, yet in the lyric sections there is a yearning loveliness that put me in mind of the fact that in October 1947 the Four Last Songs were already gestating. What a crossing of the years is here!

What is true of Don Juan is doubly true of this startlingly wonderful performance of Symphonia domestica, a work Strauss loved more than some of his public did. A 1944 performance he conducted with the Vienna Philharmonic has long been extant (Preiser, 8/95) but this London account communicates more fervently his tender and passionate belief in the piece.

The Till Eulenspiegel, which he conducted 10 days later during one of Sir Adrian Boult’s BBC SO concerts, is less remarkable, too slow and careful. Why, one asks, was the fledgling Philharmonia the more empathetic ensemble, conjuring forth phrasing and nuances the Vienna Philharmonic would have been proud to own? Beecham may be the answer. Many of the Philharmonia’s players had worked for the old wizard whose mastery of Strauss’s music went back four decades.

The hiring of the gifted and witty but barely remembered Austrian-born Jewish pianist Alfred Blumen was both personal and political. An acquaintance of Strauss, Blumen had spent the war in an internment camp in the north of England. There were reports of disagreements in rehearsal, Strauss telling Blumen to slow down, Blumen muttering how Strauss used to speed through Burleske. Neither man hangs about.

Three weeks after Strauss returned to Switzerland, Bruno Walter arrived in London to conduct the LPO in Mahler’s First Symphony. Would that it had been Mahler himself! The recording comes from a different collection of off-air acetates. These play continuously but the signal is dim and small-scale, like sound from the pre-electric era. The symphony’s atmospheric opening is also hopelessly discoloured, with wavering pitch and insecure playing. Things improve but the LPO is some way from being at its Beecham-inspired pre-war best and Walter’s conducting betrays signs of that brittleness and unease that characterised aspects of his musicmaking in the years immediately following his exile to the United States.

The 1955 Tod und Verklärung is better played and better recorded. It is a warm-toned, freeflowing performance, markedly quicker than Strauss’s own. Compared, however, with the soulsearing performance Knappertsbusch recorded in Paris the following year (also on Testament) it is all rather anodyne.