Hello, I was a pianist, I played piano while six years and since 2013 I have stopped piano. Recently, a friend called me to join her music collective composed of two singer and one beatboxer. But their level is very higher than me and I don't know if I will can.
I have always played classical music and they played contemporary music, when I went to the mini-rehearsal I wasn't able to play anything, to accompanying the singer. They told me that I'll used to it, but I think they over-estimating me, I don't know what I have to do.
Tasukete kudasai, onegaishimasu ?

Music in general is just something to get used to. Practice over and over until it's natural, kinda like you would in a sport or with driving. Just feel overall confident in yourself and you'll be able to do it. With enough enthusiasm, it'll feel like a breeze. I'm a musician, but I've only played about 2 or 3 years, but it wasn't necessary talent as much as it was confidence that I could play in bands and gigs. And overtime you'll gradually be able to pick up that talent and play so well you'll impress your friends entirely.

Did you begin practicing again? If yes, how much time do you spend on it? As someone who's been a guitarist for almost 11 years now, I play at least one hour everyday. It paid off so much! I can say I take pride in the things I'm now able to do. All that to say: daily practice is the key. One hour may seem like a lot, but really, the true professionals out there often practice over 3 hours a day (and that's a euphemism right there). I understand the pressure you're going through, I've been there too (it even gave me this huge inferiority complex that I absolutely hate). Just practice everyday. That's all you have to do. People will constantly overestimate or underestimate you, I can attest to that, but you have to understand that you don't have to be better than anyone to be talented. There's even this saying: if you're the best in a band, quit it. Don't take it 100% seriously though! I'm just saying it's okay not to be there yet, but there's a way to get to it eventually: daily practice. You just have to believe in yourself and keep going! :) Good luck! Don't forget to be yourself and take care through the whole thing!

Thank you you two for your answer, I think I have to try and work hard, practising to success. Thank you again and I will apply your advices.