Branding, as any marketing manager will tell you, is everything when it comes to selling, and when it comes to selling, classical music is no different from cars, cornflakes or shampoo. It explains why a Mahler orchestral song-cycle would fill the Royal Albert Hall while a similar work by his love-rival and near-contemporary Alexander von Zemlinsky last night left it half empty.

There is no reason why young musicians shouldn't make something special out of mature thoughts on mortality. Nor is the Albert Hall problematic when it comes to haloing intimate Bach as finely as it does massive Bruckner. The Gustav Mahler Youth Orchestra glowed in both the large scale and the small last night. Any shortcomings were in senior hands and hearts - possibly those of a usually great conductor, Philippe Jordan, more likely the infirm purpose of his composer, Bruckner. The most surprising disappointment of all came from that most prized of baritones, Christian Gerhaher.

If ever there was a Prom to put London’s classical crowd in their place, to remind us (as those outside the capital so frequently and justifiably do) that the city isn’t the be-all and end-all of concert-going, then this was it. It featured three major debuts – all of them overdue, two of them musical hand-me-downs from Birmingham.

He still looks every inch the golden boy, but Vasily Petrenko has just turned 40, and next month celebrates a decade with the Royal Liverpool Philharmonic. Time well spent, as this impressive evening revealed: after years of Russian immersion under his crisp command, here’s a band who can conjure Shostakovich’s smoudering darkness, and all the glitter and the grit in Rachmaninov’s third symphony.

If you go down to the woods today, to be sure of a big surprise is a contradiction in terms, but this pair of sylvan adventures by Matthias Pintscher and Mendelssohn was another example of the discreetly sensitive programme-building which has distinguished the present season of BBC Proms.

Karel Čapek, the great Czech writer who pioneered some of the most prophetic dramatic fantasies of the early 20th century, thought Janáček was nuts to want to set his wordy play about a 337-year-old woman to music. He could not have anticipated what that septuagenarian genius would achieve. Some of us felt similarly doubtful about singers performing this most conversational of operas with scores and music stands in a "concert staging".

It's not so long since Daniel Barenboim sat around a table with Israeli officials telling him that Wagner couldn't be played in the homeland when someone's mobile fanfared the "Ride of the Valkyries", demolishing the opposition's case. At the opposite end of the scale to all that flash of battle-lust came last night's unexpected first encore to a Wagner second half – the Act Three Prelude to Die Meistersinger von Nürnberg.

The mid-way point of the BBC Proms has just passed. Attention during the eight-week season will inevitably tend to gravitate towards the novelties, “events” and one-offs, but one pre-condition for the summer to be going well is that the Proms' backbone ensemble, the BBC Symphony Orchestra, which plays no fewer than 12 of the concerts, has to be on good form. Ideally, they should be playing well across a wide range of repertoire, they should be getting full or nearly full houses, and their relationship with their principal conductor should be positive and productive.

Superior light music with a sting, done at the highest level: what could be better for a summer lunchtime in the light and airy Cadogan Hall? Our curator was that most collegial of top soloists, trumpeter Håkan Hardenberger. He'd invited colleagues of many nations, all of them first rate, but it was almost a given that chansonnier-composer HK Gruber would steal the show.

If the BBC were to plan a Proms season exclusively devoted to youth orchestras and ensembles, many of us would be delighted. Standards are now at professional level right across the board. 20 years ago, the National Youth Orchestra of Scotland (★★★★★) couldn't compare with its Great British counterpart; now, although the age ranges are slightly different and the (or should that be the) National Youth Orchestra (★★★★) has vast wind and brass sections, playing levels appeared equal.