Organisers for the Aug 7 blockbuster Sing50 concert will have only three days to set up at the Singapore Sports Hub, when an event of such a scale usually requires about a week.

This is one of the many logistical challenges for Sing50, billed as one of the largest concerts held during the Golden Jubilee.

More than 70 artists, ranging from classical virtuosos such as Chinese pianist Lang Lang to pop stars such as Stefanie Sun will gather to perform the country's favourite melodies of the past 50 years.

They will be joined by a 1,000-strong choir, 50 pianists, the 100-strong Metropolitan Festival Orchestra and 14 rappers.

The concert is jointly organised by The Straits Times and The Business Times, and produced by non- profit arts-and-culture organisation The Rice Company. It is sponsored by Mapletree Investments, Resorts World Sentosa and Zurich Insurance, with support from Steinway Gallery Singapore

The stage will be set up only on the morning of Aug 3 because of prior events at the Sports Hub.

Says Mr Patrick Larsen, 41, chief creative officer of Pico Art International, which oversees Sing50's events management and production: "The scale of the stage was dictated by the amount of time and manpower we have. There is only so much structure a team of people can build in five days."

The main considerations behind the stage design were aesthetics and functionality, he adds.

"I created a space to help shift the focus of the audience in a natural way. There's a centre stage for main performances with components such as the choir risers, orchestra and 50 pianos around it.

"With some clever lighting and video, we can increase or decrease the stage's perceived size to make the performance more intimate or grand."

There will also be an "eclectic mix of visual styles, from psychedelic Sixties to contemporary graphic animation", says the concert's multimedia director, multimedia artist Brian Gothong Tan, 35.

"I sat down with Jeremiah Choy, Sing50's creative director, and we went through the emotions we wanted to evoke for each act and how to integrate them with costumes and lighting," he adds.

Another mammoth task will be transporting the 52 pianos used in the concert - 50 of these are baby grand pianos to be used by pianists in a segment led by Lang Lang, who will play a Red Concert grand piano. The last piano will be used by local musicians Dick Lee, Jeremy Monteiro and JJ Lin.

To disassemble and move the pianos, 40 specialist movers have been hired, while four hydraulic trucks will move them from Tanglin Trust School, the concert's rehearsal site, to the Sports Hub. Each piano is covered with canvas sheets to shield them from weather elements, says Steinway Gallery Singapore's general manager Celine Goh.

The process will be a race against the clock, as the team has just two hours to unload all 52 pianos at the venue and move them on stage. The final tuning will take place in the wee hours on Aug 4, between 4 and 9am, as the sound check schedule is tight.

The organisers are working closely with contractors to minimise the concert's impact on the Sport Hub's grass pitch, says Sing50's technical director Alan Meng, 50.

Another key challenge for the concert's sound crew is to cater to the sounds of artists across different genres, he notes.

"We've worked with the music directors to rearrange some of the pieces and the audio engineers to make sure everything, from the choral singers to the instruments, is picked up on the microphones. It's important as Sing50 is all about showcasing our music."