Although the evening Proms slots remain the most popular, the lunchtime and late-night concerts also attract large audiences, and often contain gems with lesser-known artists and works. The Proms season is mainly known for its large-scale classical music concerts, but does also encourage a diverse range of styles, as a cappella group Naturally 7 demonstrated on Monday evening.

Naturally 7 formed in the late 1990s in New York, with seven men who had enjoyed singing together in church and combining their voices. They developed a unique style which they call “VocalPlay”, and have since travelled the world and supported Michael Bublé and Coldplay on tour. Although their music shows influences from gospel, classical, jazz, pop and R&B, as well as rap and beatboxing, they have maintained their own sound. As The Boston Globe said in November 2010, “To call them an a cappella group would be a gross understatement”. The group all have strong singing voices, but they can also create the sounds of instruments, which they use to accompany their songs. Among them, they create electric guitars, harmonicas, trumpets, clarinets, cellos, basses and full drum kits – all using only their voices.

The late-night concerts always have a more intimate feel, and it was beneficial to hear all the members of the band introduce the songs. It was clear they were presenting us with their best hits, and the programme seemed well rehearsed and slick, with lots of energy and personality. They had good, natural choreography which aided the singing, and they all interacted with each other and the audience well, and ensured that everyone had fun. The chosen pieces allowed every group member to shine, each taking the lead at some point. They arranged themselves to look like a typical band with “percussion” and “guitars” at the back and singers at the front. As they produced the instrumental sounds they also acted out playing it, for example strumming a guitar or blowing a trumpet, a constant reminder we were listening only to voices and not to a backing track. The only electrical equipment on stage was a looping machine and seven microphones, and the extended guitar solos and amazing drum riffs sounded like the real thing.

The group uses their own arrangements, written by musical director and first baritone Roger Thomas. The most memorable songs of the night were Coldplay’s Fix You, Bob Marley’s One Love, Phil Collins’ In the Air Tonight and an arrangement of Joshua Fit the Battle of Jericho. In Fix You particularly, they added their own harmonies to make this song, which is so often covered, their own.

The one song the group sang off-microphone showed their raw talent: here not masked by the extraordinary instrumental sounds, we heard the seven rich singing voices blending beautifully. It was a big change from their other, louder numbers, but they managed to fill the hall with this Simon & Garfunkel medley, including The Sound of Silence, Scarborough Fair and April Come She Will.

The only drawback of the night was the microphones favouring the vocal percussion, with the lead vocals occasionally getting lost. It would have been even better to hear more pure a cappella music minus the microphones (which is after all how the group started), and also to have explored more musical styles – they mainly stuck to pop and R&B.

Initially worried about the fact that this group are used to a different kind of audience and venue, I found them hugely well received; people were in awe of their vocal techniques, joined in by clapping and singing along, and gave two standing ovations. It is brilliant that the Proms support various musical styles, resulting in educational and enjoyable evenings for all.