The fourth country to rehearse today was Latvia, and the vocal group Cosmos with the song I hear you heart. However in a song that you possibly thought couldn't have a gimmick, an additional member makes an appearance on stage. This is a small puppet figure that joins in towards the end of the song, assembled from what looks like a folder and microphones! The whole effect is quite amusing, if a little bewildering.

As a song that largely relies on the vocals, it was not surprising that a lot of time was taken up with the group getting the balance right with their microphones, as well as vocally warming up before their run throughs of the song. In the rehearsals the lighting was mainly an orange colour, with the wings of the set moving up and down quite a lot.

It was just the six members of the group who faced the fans and journalists for the press conference, and it was vocal treat for those present. There was much more singing than there was questions, and appropriately enough the first piece of music was the theme music for the Eurovision network Te deum. There then followed a request for a Greek song, so the audience was treated to Goodbye my love. Further songs were the Michael Jackson hit Billie Jean and they ended up with another European anthem, Beethovens' 9th Symphony, also known as Ode to joy.

• Click here to watch a compilation

Are you satisfied with the first rehearsal? "Yes, the sound and lighting engineers are very good and we are very happy that everyone does their job very well".

How did you all meet? "We all came from boys' choirs, and that's how we met. We then wanted our own small choir, and then tried something a little bit different, and then we tried pop, so we are not a boy band, it was a natural compilation that brought us together. We think that this is the first time ana cappella song has been in the Eurovision song contest, and it is very interesting for us".

Latvia has done very well in the history of the contest coming in the top five, in three out of the six contests. So, how important is it for you to do well on Saturday? "We hope to do our best, and that the people will like us. It is important to have a nice evening, a celebration of a love for music. For Latvia it is very popular, almost half the population will watch, so its very important to be good".

How do you choose the songs you perform, do you compose? "We do both our own songs and cover versions. This song for the contest was composed by two of the group Andris and Reinis. Our goal is to make music with no instruments".

Do you have any favourite Eurovision song contest songs from the past? "Diva"and"Sanomi"

How did you come up with the name Cosmos? "Well it is a Greek name (Global), we liked that fact, with different styles of music, and it's classical and academic. We can do pop, funky hip hop. We have no borders, direction. So, that is the connection".

You have a seventh performer on stage, which could be said to break the rules?They jokingly replied: "Well he is actually our virtual manager, that walks on stage with us,you can't call the doll a man…just like our manager!"

The six performers of the group Cosmos, together with their virtual manager will return tomorrow for their second rehearsal at 12:30