Background: Bocelli was born to Alessandro and Edi Bocelli. Doctors had advised Bocelli's parents to abort Bocelli before birth as they predicted, based on studies, that Bocelli would be born with a disability. It was evident at birth that Bocelli had numerous problems with his sight, and after visits to many doctors, he was diagnosed with congenital glaucoma. Bocelli has stated that his mother's decision to give birth to him and overrule the doctor's advice was the inspiration for him to oppose abortion.
Context: As winner of the newcomers section at the 1994 Sanremo Festival, Bocelli was invited to return the following year. He entered the main competition with "Con te partiro" and finished in fourth place. The song was included on his second album, Bocelli, produced by Mauro Malavasi and released in November 1995. In Belgium, "Con te partiro" became the best-selling single of all time. His third album, Viaggio Italiano, was released in Italy in 1996. He was invited to sing a duet with English soprano Sarah Brightman at the final bout of German boxer Henry Maske. Brightman had approached Bocelli after she heard him singing "Con te partiro" whilst she was dining in a restaurant. Changing the title lyric of the song to "Time to Say Goodbye", they re-recorded it as a duet with members of the London Symphony Orchestra and sang it as a farewell for Maske. The single debuted atop the German charts, where it stayed for fourteen weeks. With sales nearing three million copies, and a sextuple platinum award, "Time to Say Goodbye" eclipsed the previous best-selling single by more than one million copies. He topped the Spanish singles chart in 1996 with a duet with Marta Sanchez, "Vivo Por Ella", the Spanish version of "Vivo per lei", recorded with Giorgia for his 1997 compilation album, Romanza. He also recorded a Portuguese version of the song with Brazilian singer Sandy. The same year, Bocelli recorded "Je vis pour elle", the French version of "Vivo per lei", as a duet with French singer Helene Segara. Released in December 1997, the song became a hit in Belgium (Wallonia) and France, where it reached No. 1 on the charts. To date, it is the best-selling single for Segara, and the second for Bocelli after "Time to Say Goodbye". On 3 March, he appeared in Hamburg, Germany, with Sarah Brightman to receive the ECHO music award for "Best Single of the Year". In the summer of 1997 he gave 22 open-air concerts in Germany, and an indoor concert in Oberhausen on 31 August. In September, he performed in concert at the Piazza dei Cavalieri in Pisa for the home video A Night in Tuscany (Italian: una notte nella Toscana) with guests Nuccia Focile, Sarah Brightman and Zucchero. The concert was also Bocelli's first concert to air on PBS part of the In The Spotlight series. It also marked as Bocelli's debut to the American audiences. On 14 September, in Munich, Germany, he received an ECHO Klassik Best Seller of the Year award for his album, Viaggio Italiano. Back in Italy in Bologna on 27 September, he sang at the International Eucharistic Congress. On 19 October, he sang at the TeleFood benefit concert held in the Vatican City to raise awareness about world hunger. On 25 October, he received a Bambi Award in the Klassik category in Cologne, Germany. CANNOTANSWER
Question: What did he sing?

Answer:

singing "Con te partiro" whilst she was dining in a restaurant.