Hi Katia, I’m thinking ‘pandemically’ that we’ll need to find some future ‘work-arounds’ to wisely select our music. Not that too many local sheet-music stores ever had huge recorder sections. I can only speak to one of the books you asked-about. “Baroque Recorder Anthology 3” (ed. Bowman & Heyens) is one from that series that I play from. The music selections are from the less ‘big-box-office’ composers yet of high quality. I love the selections. You’ll find that it’s published by Schott in Germany, who offers a very friendly PDF preview of the book on their website.
https://en.schott-music.com/shop/pdfviewer/index/readfile/?idx=MzY2NDM=&idy=36643
The book comes with a CD of mp3 files – two for each musical piece. One is the piece played on expertly on recorder with harpsichord accompaniment and the other is just the harpsichord. A=440. While some book series may offer slow and fast cuts of accompaniment, both here are at full performance speed. To accommodate my tired old hands and eyes, I downloaded the Open Source “VLC Media Player” which permits playing the accompaniment at a number of lower speeds while staying at the same pitch, and of course it has a repeat setting as well.
Please note that the series has four books for the Renaissance and four Baroque. Requesting them mail order can be tricky as for each musical period only Book ‘3’ and Book ‘4’ are for Alto. Books 1 and 2 are Soprano books with totally different pieces of music. As an Alto player then, there are four anthology books in this series for your (our) instrument.
I should add that the long established recorder shops that are on line have sheet-music comments and suggestions that I often find very helpful. You might check the comments given on the websites of Courtly Music Unlimited and Antique Sound Workshop. (The owners are recorder players)
Amazon has to be ‘worked’ to get a sense of their sheet-music marketplace. Writing “best selling alto recorder sheet music” in their search engine got me (supposedly) their top 450 Alto sheet-music books (I think) in sales order. You must keep an eye on the other list filters. I think “Featured” means the books they are perhaps pushing. There is an occasional flag of “Best Seller.” I watch for how many highly ‘stared’ reviews have been posted for a work and make sure I read the comments posted in the ‘worst’ reviews as well the best, remembering that I have to judge the musicianship of the reviewer carefully. Also keep an eye on Amazon’s cover picture of a book you’re considering. Amazon sometimes has a “Look Inside” button there that may then show the Table of Contents and – with luck – some music pages by which to judge somewhat the difficulty of a book.
Posting your inquiry here was a very good start. I’m afraid we’re all going to be doing a bit of detective work to find good musical pathways during the isolation of this pandemic. Best of luck on your search; best of luck in your music! – k –